Add CodeActions for Number Constants: Convert between bases, Add digit group separators

[Booksbaum]

Some Code Actions for number SynConsts:
(inspired by dotnet/fsharp#3043 & dotnet/fsharp#3044)

Convert between bases/formats:

• Convert between int bases (decimal, hex, octal, binary):
  
  • supports all ints (sbyte, byte, int16, uint16, int, int32, uint, uint32, nativeint, unativeint, int64, uint64) and floats (float, float32) in hex/oct/bin form
• Convert between char formats (char, decimal, 3 hexs):
  
  • No CodeAction to convert to char representation when not a visible char (Char.IsControl check) (except escape sequences -- \n and co are handled)
  • supports byte char too:
    
  • Note: currently not available for 2-digit hex & 8-digit-utf32 hex (see dotnet/fsharp#15867),
    but is just uncommented (incl. tests) -> should be un-uncommented once PR (dotnet/fsharp#15898) is merged
  • Also available when in int form:
    
• Note: no Convert between decimal & scientific notation for floats: not precise/too precise/not lossless with float value and I wasn't in the mood to implement conversion based on strings....
• Note: no Convert between float & int notation for floats: issues with precision/rounding
• Note: I try to preserve existing signs (including unnecessary ones like a +). But sometimes it's necessary to add or change the sign
  • for example with negative bit: 0b1010_0101y -> -91y: decimal requires a minus sign
  • But also means: not reversible: 0b1010_0101y -> -91y -> -0b1011011y

Replace with Named Constant (MinValue, MaxValue, ±infinity, nan, Epsilon):

Extract/Integrate Minus:

• for Hex/Oct/Bin formats
• Additional Actions for other shenanigans with signs:
  
  

Add digit group separators:

• for ints: group length based on format:
  
  • group lengths:
  • decimal: thousands (3)
  • hex: words (4), bytes (2)
  • octal: 3 (is there a special name?)
  • binary: nibbles (4), bytes (8)
• for floats: always 3-digit-groups, and always for all parts (int, decimal, exponent):
  
  • when float in int form: see ints
• when at least one group separator exists: QuickFix to remove separators:

Pad binary with 0s:

• Available target lengths: 4, 8, 16 bits
• Or should I change this to pad to next full 4 or 8 bit? (So if I have 0b101 I would Pad to next 8 bit to get 0b00000101 and then additional Pad to next 8 bit to get 0b0000000000000101)

Some Additional Notes:

• To prevent errors with newly added sign I add a space when operator char immediately before:

  //             -91y
  let value = 5y+0b1010_0101y
  
  // => Convert to decimal
  
  // without space:
  let value = 5y+-91y
  //            ^^
  //            The type 'sbyte' does not support the operator '+-'
  
  // with space:
  let value = 5y+ -91y

  But I'm not sure I handle all cases a new sign might lead to invalid code.
  I currently check for leading !$%&*+-./<=>?@^|~ (F# operator chars).
  Are there any other cases a number is valid immediately after something else but with additional sign it turns into an error?

[Booksbaum]

Ok...CI errors are because fantomas now respects .editorconfig (was incorrect pattern match for fs-files)
-> quite a lot of files need reformatting...

I just apply new formatting too all. If that's not ok we should adjust settings in .editorconfig