ges: Register formatters during meta registration

So that formatters implemented outside GES itself are registered
8 jobs for formatter_fixes in 14 minutes and 26 seconds (queued for 1 second)
Status Name Job ID Coverage
  Preparation
passed gst indent #80800

00:00:18

passed manifest #80799

00:00:19

 
  Build
passed build fedora x86_64 #80801

00:02:56

 
  Test
passed check fedora #80802

00:03:01

 
  Full Builds
passed build android arm64 api28 #80803

00:04:35

passed build cerbero cross win32 #80805

00:07:51

passed build cerbero cross win64 #80806

00:05:41

passed build cerbero fedora x86_64 #80804

00:08:08