Make ``QkTarget`` ask for a `name` for fixed parameter entries.

[raynelfss]

What should we add?

To make the behavior of Target more consistent with the way it works in Rust, we should be able to pass a different name to gates with fixed parameters being passed to the Target.

For example:

QkTarget target = qk_target_new(1);

// This explicitly says the target only supports Rz gates with half rotations.
double rz_params[1] = {3.14};
QkTargetEntry *rz_pi_entry = qk_target_entry_new_fixed(QkGate_RZ, rz_params, "rz_pi");
// Add properties ....
qk_target_add_instruction(target, rz_pi_entry);

// This explicitly says the target also supports Rz gates with quarter rotations.
double rz_quart_params[1] = {1.57};
QkTargetEntry *rz_quart_entry = qk_target_entry_new_fixed(QkGate_RZ, rz_quart_params, "rz_quart");
// Add properties ....
qk_target_add_instruction(target, rz_quart_entry);

// This should adopt the gate's name by default as it can take any parameter for this gate.
QkTargetEntry *rx_entry = qk_target_entry_new(QkGate_RX);
// Add properties ....
qk_target_add_instruction(target, rx_entry);

This will also appeal more to the way we will be querying the QkTarget via #15184.