Those diagrams, versions of which have been reproduced in many different flight training "ground school" materials, including some published by the FAA, are extremely misleading, and contain errors and omissions.
Slips and skids are not characterized by an "imbalance" between the pseudoforce called "centrifugal force", and the horizontal component of the net aerodynamic force generated by the aircraft.
Rather, slips and skids are characterized by an imbalance between the pseudoforce called "centrifugal force", and the horizontal component of the wing's lift force.
Since the pseudoforce called "centrifugal force" is really just a mirror image of the horizontal component of the net aerodynamic force generated by the aircraft, the above statement is just a really complicated way of saying that in a slip or skid, something other than the wing's lift vector is generating an aerodynamic force which has a horizontal component.
That "something" is the fuselage. In a slip or skid, the airflow is striking the side of the fuselage, which generates a real aerodynamic sideforce, oriented perpendicular to the wing's lift vector. Because the fundamental defining characteristic of a slip or skid is that the nose of the aircraft is not aligned with the actual direction of travel though the airmass, in the yaw axis.
If the aerodynamic sideforce generated by the airflow striking the side of the fuselage were included in the diagrams attached to the question, the horizontal component of the net aerodynamic force generated by the aircraft would be exactly equal in magnitude (and opposite in direction) to the "centrifugal force" vector in every case.
If the vectors labelled "HCL" are supposed to represent the horizontal component of the net aerodynamic force generated by the aircraft, including the horizontal component of the aerodynamic sideforce generated by the airflow striking the side of the fuselage, then they are drawn incorrectly. They should be mirror images of the vectors labelled "centrifugal force".
On the other hand, if the vectors labelled "HCL" are only supposed to represent the horizontal component of the wing's lift vector, then they are drawn correctly, but the diagrams are very misleading because the vector representing the horizontal component of the aerodynamic sideforce generated by the airflow striking the side of the fuselage has been entirely omitted. Also, if the vectors labelled "HCL" are only supposed to represent the horizontal component of the wing's lift vector, then by logical extension the vectors labelled "VCL" must be intended to only represent the vertical component of the wing's lift vector, not the vertical component of the net aerodynamic force generated by the aircaft. In which case the vectors labelled "VCL" should not be all the same length, because in a slip, the aerodynamic force from the air striking the side of the fuselage includes an upward vertical component which supports some of the aircraft weight and reduces the vertical force that the wing must generate, while in a skid, the aerodynamic force from the air striking the side of the fuselage includes a downward vertical component which increase the vertical force that the wing must generate.
Obviously the diagrams would be greatly improved by changing to an airmass-based reference frame rather than an aircraft-based reference frame, so that the "centrifugal force" vector could be entirely discarded, and by also including the aerodynamic force vector generated by the air striking the side of the fuselage. There's no need to break things into horizontal and vertical components, just show the wing's lift vector and the aerodynamic sideforce vector from the airflow striking the side of the fuselage. These two vectors are oriented perpendicular to each other. In a coordinated turn, there is no airflow striking the side of the fuselage, so the aerodynamic sideforce vector is zero, so the net aerodynamic force acts "straight up" in the aircraft's reference frame. In a slip or a skid, the aerodynamic sideforce vector is not zero, and so the net aerodynamic force does not act "straight up" in the aircraft's reference frame. End of story.
This concept was also explored in this related, highly upvoted question-- What is missing from these diagrams of the forces in slips and skids?
But as to your specific question:
If in a coordinated turn, the horizontal lift vector is equal to the Centrifugal force. Then how is the aircraft still turning?
Because when include the pseudoforce called "centrifugal force" in our vector diagrams, we are using an aircraft-based reference frame rather than an airmass-based reference frame or ground-based reference frame. Since the aircraft can't accelerate relative to itself, the net force in the aircraft-based reference frame will always be zero, whether the aircraft is turning or not. In the aircraft-based reference frame, the fact that the centrifugal force vector exists at all is actually evidence that the aircraft is turning. You can see from the preceding parts of this answer that the author of this answer feels that using the aircraft-based reference frame (and therefore including the "centrifugal force" vector whenever the flight path is not linear) is an inferior approach to using the airmass-based reference frame (and therefore not including any "centrifugal force" vector.)