As a follow up to #142 we can now add tags to diagnostics for specific plugins.
This would likely need to be based on matching the error codes.

• pylint (https://pylint.pycqa.org/en/v2.12.2/technical_reference/features.html):
  • Deprecated:
    • W0402: Uses of a deprecated module %r
    • W1505: Using deprecated method %s()
    • W1511: Using deprecated argument %s of method %s()
    • W1512: Using deprecated class %s of module %s
    • W1513: Using deprecated decorator %s()
  • Unnecessary:
    • W0611: Unused import %s
    • W0612: Unused variable %r
    • W0613: Unused argument %r
    • W0614: Unused import %s from wildcard import
    • W1304: unused-format-string-argument
• pycodestyle (https://pycodestyle.pycqa.org/en/latest/intro.html#error-codes):
  • Deprecated: all codes starting with W6
• flake8 (https://flake8.pycqa.org/en/latest/user/error-codes.html):
  • Unnecessary:
    • F401: module imported but unused
    • F504: % format unused named arguments
    • F522: .format(...) unused named arguments
    • F523: .format(...) unused positional arguments

I think it's worth the effort, but wanted to first see if you agree. Happy to make a PR with the changes.