Try to use Projectile to find files in *compilation* buffer if possible.

If not, fallback to the original function.

* projectile.el (projectile-compilation-find-file): Use projectile to find
files in *compilation* buffer if possible.

(projectile-mode): Add the previous function around `compilation-find-file'.

Add/Remove the advice around `compilation-find-file' when the mode is on/off.
Shouldn't we first try to find the file using `compilation-find-file`. Often the paths will be either absolute or relative to the `default-directory` and using Projectile for those would be an overkill.