Live update

[Salzian]

This PR introduces the Live Update feature of FMOD studio. It's a simple flag, but I want to only include it to developers if they use a special flag. So they don't accidentally enable it in release builds.

[GitGhillie]

It works but I'm getting some warnings when not using the feature:

PS C:\Rust\bevy_fmod> cargo run --example minimal
warning: unused import: `FMOD_STUDIO_INIT_LIVEUPDATE`
 --> src\fmod_studio.rs:8:31
  |
8 |     FMOD_INIT_3D_RIGHTHANDED, FMOD_STUDIO_INIT_LIVEUPDATE, FMOD_STUDIO_INIT_NORMAL,
  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: variable does not need to be mutable
  --> src\fmod_studio.rs:56:13
   |
56 |         let mut studio_flags = FMOD_STUDIO_INIT_NORMAL;
   |             ----^^^^^^^^^^^^
   |             |
   |             help: remove this `mut`
   |
   = note: `#[warn(unused_mut)]` on by default

Can you please fix these?

[GitGhillie]

Looking good