feat(experimental): Parse match expressions

[jfecher]

Description

Problem*

Working towards #988

Summary*

Add parser, formatter, lsp support for match expressions

Additional Context

Still can't use these in a program, we panic in the monomorphizer for them. Just pushing these somewhat trivial changes before the chunkier changes of compiling match expressions to a decision tree, checking for completeness, redundancy, then monomorphizing etc.

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Test Suite Duration'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.20.

Benchmark suite	Current: 4d07680	Previous: 0c6c637	Ratio
noir-lang_noir_string_search_	1 s	0 s	+∞
noir-lang_mimc_	1 s	0 s	+∞
noir-lang_eddsa_	2 s	1 s	2
AztecProtocol_aztec-packages_noir-projects_noir-protocol-circuits_crates_blob	61 s	49 s	1.24

This comment was automatically generated by workflow using github-action-benchmark.

CC: @TomAFrench

[jfecher]

(ready for review now)