Added support for ImHex's Pattern Language

[WerWolv]

Description

This Pull Request aims to add support for ImHex's Pattern Language.
Some special considerations here:

• The Pattern Language is meant for specifying and decoding binary file formats. While it's not necessarily a file type that's only expected to appear once per repository, most repos still won't have a large amount of them since 1 file = 1 file format generally
• We have a database repository where lots of people contributed their pattern to if they don't want to make a separate repo and want to include their format in ImHex. It might therefor show up more often in the search but in my opinion should still be considered since the files are contributed by many different people

Checklist:

• I am adding a new language.
  • The extension of the new language is used in hundreds of repositories on GitHub.com.
    • Search results for each extension:
      • Search for .hexpat
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • [URL to each sample source, if applicable]
    • Sample license(s):
  • I have included a syntax highlighting grammar: https://github.com/WerWolv/PatternLanguage-Grammar
  • I have added a color
    • Hex value: #3a6be0
    • Rationale: Part of ImHex's Logo color
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

See inline comments.

[WerWolv]

Fixed the issues, thank you 👍