Remove spritesheet dependency from loader, fix resources type

[bigtimebuddy]

Replaces #7295

• Remove the @pixi/spritesheet dependency from @pixi/loaders
• Fix the resources type for Loader to be more strict (e.g., contains texture) credit: @AdrienLemaire
• Added some additional documentation for Loader interfaces

[codecov]

Codecov Report

Merging #7300 (f2e1363) into dev (f6d9404) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               dev     #7300   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           17        17           
  Lines          699       699           
=========================================
  Hits           699       699           

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[ShukantPal]

webdoc doesn’t actually read declaration (global.d.ts) files so I’d be careful placing documentation there.

[bigtimebuddy]

Understood on webdoc @SukantPal With these mixins we will probably need to add both global docs (for TS tooltips) and src docs (for webdoc).