Make FPS updates activatable at runtime

[pecoram]

Currently, renderOptions.fpsUpdateInterval enables FPS updates when set to a value different from 0, but it can only be defined at creation time and cannot be modified dynamically.

It would be beneficial to allow changing this value at runtime, enabling or disabling performance monitoring without requiring a complete reinitialization.

Use Case:
In some scenarios, developers may want to enable FPS monitoring only under specific conditions (e.g., debugging or performance profiling) and disable it dynamically when not needed at runtime.

[michielvandergeest]

@pecoram yes this is a valid use case and it makes sense to enable this behaviour

I've discussed the issue with @Drulokia and we'll be expanding on this request by making all renderer settings updatable during runtime (those where it makes sense at least), versus a one time setting at initialisation as it is now