Add QuickBASIC

[DecimalTurn]

Description

This PR adds QuickBASIC (QB) as a langauge for the .bas extension.

Note that there exists a modern version of QuickBASIC known as QB64 that is still compatible with Classic QB. Since Classic QB and QB64 haven't reached the popularity threshold by their own at the moment, I've kept them combined, but we could seperate them in the futur if popularity justifies it.

The grammar used is the one for QB64, since it is also compatible with Classic QB.

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 query (3k+ results)
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • QuickBASIC samples:
        • https://github.com/skeeto/scratch/blob/master/sp4/sponge4.bas (Unlicense license)
        • https://github.com/DualBrain/QuickPakPro/blob/main/QB64/FGETRT.BAS (MIT)
        • https://github.com/DualBrain/QuickPakPro/blob/main/QB64/VLONG.BAS (MIT)
      • Extra BASIC samples (to help classifier):
        • https://github.com/yantrabuddhi/bwbasic3/blob/a062bd4a05fb9459d6e8188c4185638ccad04df7/NBS2/P180.BAS (GPL 2)
  • I have included a syntax highlighting grammar: https://github.com/QB64Official/vscode
  • I have added a color
    • Hex value: #008080
    • Rationale: Based on the green at the bottom of the QuickBASIC IDE.
  • I have updated the heuristics to distinguish my language from others using the same extension.