Use mimetypes as identifiers

[Nova38]

Migrate to using mimetypes as identifiers instead of all-caps Litteral str

Describe the solution you'd like

Transition away from using raw strings as the filetype identifiers. This would standardize what plugins should expect to receive or produces.

1. have the shape of 'type/subtype' ie application/java-archive

The one area that has been identified as a concern is being handling ambiguity and not having different file types map to the same mimetypes. This would need a little work but could be implemented by exposing some utility functions to the plugins. Additionally for compatiblity with older custom plugins their could be a centralized map of the older used identifies to the new equivalent mimetypes

Additional context

• Python stdlib mimetypes https://docs.python.org/3/library/mimetypes.html
• Polyfile uses them https://github.com/trailofbits/polyfile/blob/5b7dc0c66a65a7c22a783395e669fe6b964753d0/polyfile/polyfile.py#L220
• https://www.iana.org/assignments/media-types/media-types.xhtml
• https://datatracker.ietf.org/doc/rfc2046/
• This spdx v3 uses this in their mediatype type: spdx-spec MediaType