Add code action to format code when there's a "multiple statements" warning

[luabud]

Ref: #43

There are two things that needs to be done:

• Create quick fix for warning code C0321:multiple-statements that triggers the format document action
• Add unit test

The code for the first step will be similar to the one here:

vscode-pylint/bundled/tool/server.py

Line 243 in 2fae19e

@QUICK_FIXES.quick_fix(codes=["C0301:line-too-long"])

And the unit tests will be similar to this:

vscode-pylint/src/test/python_tests/test_code_actions.py

Line 23 in 2fae19e

"C0301:line-too-long",

[gagandeepp]

@luabud interested please assign