feat(compiler): Allow omitting field name in struct creation [LNG-261]

[InversionSpaces]

Description

Allow omitting field name in ability or data construction if it is the same as the passed variable for convenience:

field = 42
st = Struct(field) -- same as Struct(field = field)

Also the same for .copy method.

Implementation Details

• Rewrite parsing to accept short arguments in .copy and constructors
• Process parsing results on semantics stage accordingly

Checklist

• Corresponding issue has been created and linked in PR title.
• Proposed changes are covered by tests.
• Documentation has been updated to reflect the changes (if applicable).
• I have self-reviewed my code and ensured its quality.
• I have added/updated necessary comments to aid understanding.

Reviewer Checklist

• Tests have been reviewed and are sufficient to validate the changes.
• Documentation has been reviewed and is up to date.
• Any questions or concerns have been addressed.

[linear]

LNG-261 Allow omitting field name in struct creation

data Struct:
  integer: i8
  str: string

func main():
  str = "string"
  i = 42
  st = Struct(str, integer = i) -- not `str = str`

Also would be beneficial for abilities.

[InversionSpaces]

Task for docs: LNG-264