Improve tabSize configuration based off file types [Feature Request]

[rajinder-yadav]

What exist today is very limited, a one size fits all don't work for most people:

  "editor.tabSize": 4,

A suggested improvement:

  "editor.tabSize": {
     "default": 4,
     "web": 2,
     "cpp": 3
   }

   // Don't need to specify the '.' before extension name.
   // Specify multiple extensions with '|' or separator.
   tabFileExtensions: {
    "cpp": ['h|hpp|c|cpp|cc'],
    "web": ['js|html|css|ts']
   }

[sandy081]

We are planning to implement file based configurations in which this will be covered

[sandy081]

Duplicates #1587