checker: handle casted type matches

[Delta456]

Closes #19248

🤖[deprecated] Generated by Copilot at cce27af

This pull request adds type checking and casting logic for match expressions in the vlib/v/checker module. It also adds several test files in the vlib/v/checker/tests directory to verify the correct behavior and error messages for different cases of match expressions with type casts.

🤖[deprecated] Generated by Copilot at cce27af

• Add variables and logic to check type consistency and casting requirement in match expressions (link, link, link)
• Declare explicit_cast_type and need_explicit_cast to store the expected type and the flag for explicit type casting in match branches (link)
• Assign explicit_cast_type to the type of the first branch and check if it is a cast expression (link)
• Compare the type and the casting of the rest of the branches with explicit_cast_type and need_explicit_cast and report errors if they are not consistent (link)
• Add test files for different scenarios of type casting in match expressions (link, link, link, link, link, link)
  • Add test for match expression with incorrect type cast in one branch (match_incorrect_cast_branch_err.vv and match_incorrect_cast_branch_err.out) (link, link)
  • Add test for match expression with type cast only in the last branch (match_last_branch_only_casted.vv and match_last_branch_only_casted.out) (link, link)
  • Add test for match expression with no type cast in any branch except the first one (match_no_branch_cast_rest_casted_err.vv and match_no_branch_cast_rest_casted_err.out) (link, link)

[spytheman]

Good work.