Feat(SwiftRefactor): Implement RemoveRedundantParens refactoring

[rickhohler]

Description

This PR implements the RemoveRedundantParens refactoring action, which safely unwraps single-element tuples that do not need parentheses.

Transformation:

let x = (10)
// becomes:
let x = 10

Detailed Design

• Adds RemoveRedundantParens provider to SwiftRefactor.
• Criteria:
  • Input is a TupleExprSyntax.
  • Exactly one element.
  • No element labels.
• Safety Logic (Precedence):
  • To prevent breaking operator precedence, the refactoring aborts if it detects that it is unwrapping a SequenceExpr (binary operation) inside another SequenceExpr (or standard ExprList structure).
  • Example: x * (a + b) -> Parentheses are PRESERVED (Refactoring unavailable).
  • Example: let x = (a + b) -> Parentheses removed (Safe assignment).

Fixes

Addresses core logic for swiftlang/sourcekit-lsp#2451.

Pre-PR Checklist

• Code builds and passes tests.
• Ran swift-format.
• Added unit tests in RemoveRedundantParensTest.swift.