[SwiftParser] Improve attribute parsing and recovering #303

Job	Run time
Validate generated code	2m 57s
Run tests using swift-syntax-dev-utils (Windows)	40m 41s
Run tests using swift-syntax-dev-utils (Linux)	24m 42s
Test / Linux (5.10 - jammy)	3m 59s
Test / Linux (5.9 - jammy)	3m 57s
Test / Linux (6.1 - jammy)	4m 13s
Test / Linux (6.0 - jammy)	4m 13s
Test / Linux (nightly-main - jammy)	4m 48s
Test / Linux (nightly-6.2 - jammy)	5m 10s
Test / macOS (Xcode ${{ matrix.xcode_version }} - ${{ matrix.os_version }} - ${{ matrix.arch }})	0s
Test / Windows (nightly - windows-2022)	15m 51s
Test / Windows (6.0 - windows-2022)	12m 32s
Test / Windows (5.9 - windows-2022)	16m 33s
Test / Windows (6.1 - windows-2022)	12m 37s
Test / Swift SDK for Wasm Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	0s
Test / Static Linux Swift SDK Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	0s
Test / Windows (nightly-6.2 - windows-2022)	15m 44s
Test / Embedded Swift SDK for Wasm Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	0s
Soundness / API breakage check	0s
Soundness / Documentation check	4m 39s
Soundness / Unacceptable language check	5s
Soundness / Broken symlinks check	5s
Soundness / Python lint check	7s
Soundness / Format check	39s
Soundness / Shell check	39s
Soundness / YAML lint check	6s
Soundness / License headers check	13s
	2h 54m 30s

Provide feedback