[Minor][Engg]: Add Swift Lab API models: enums and LabTestApplication

[josephpab]

Part 1 of incremental Lab API Swift migration. Adds new Swift types alongside existing ObjC lab_api code (no behavior change).

• LabAPIEnums.swift: 12 Swift enums replacing ObjC string constants (AccountType, MFAType, ProtectionPolicy, B2CProvider, etc.)
• LabTestApplication.swift: Codable struct replacing MSIDTestAutomationApplication with type-safe decoding

These files compile in IdentityAutomationTestLib but are not yet referenced by any consumers. Old ObjC code continues to run.

PR Checklist (must be completed before review)

• All tests pass locally
• PR size is <= 500 LOC per PR Size Check policy
• PR is independently mergeable (no hidden dependencies)
• Appropriate reviewers are assigned
• PR reviewed by code owner (required if Copilot-generated)
• SME or Senior IC assigned where required

PR Title Format

Required Format: [Keyword1] [Keyword2]: Description

• Keyword1: major, minor, or patch (case-insensitive)
• Keyword2: feature, bugfix, engg, or tests (case-insensitive)

Examples:

• [MAJOR] [Feature]: new API
• [minor] [bugfix]: fix crash
• [PATCH][tests]:add coverage

Proposed changes

Describe what this PR is trying to do.

Type of change

• Feature work
• Bug fix
• Documentation
• Engineering change
• Test
• Logging/Telemetry

Risk

• High – Errors could cause MAJOR regression of many scenarios. (Example: new large features or high level infrastructure changes)
• Medium – Errors could cause regression of 1 or more scenarios. (Example: somewhat complex bug fixes, small new features)
• Small – No issues are expected. (Example: Very small bug fixes, string changes, or configuration settings changes)

Additional information

[josephpab]

@copilot review this PR

[Copilot]

@copilot review this PR

Reviewed. The enums in LabAPIEnums.swift are correct and match the ObjC constants exactly. I found and fixed several issues in LabTestApplication.swift (commit a78f6db):

Bugs fixed:

1. Abbreviated license headers — Both new files used a 4-line shorthand; updated to the full MIT license text matching every other file in the repo.

2. multiTenantApp decoding — The original code tried to decode this as Bool, but the Lab API returns "Yes"/"No" strings (matching ObjC: isEqualToString:@"Yes"). Fixed with caseInsensitiveCompare("yes").

3. JSON key mismatches — The CodingKeys used Swift property names instead of the actual API field names:

   • redirectUri (singular, from ObjC @"redirectUri") → was incorrectly mapped to "redirectUris"
   • authority (from ObjC @"authority") → was incorrectly mapped to "defaultAuthorities"

4. defaultScopes/defaultAuthorities type — The ObjC model parses these from comma-separated strings (via msidOrderedSetFromCommaSeparatedString:), not native JSON arrays. Updated Swift decoding to split by comma consistently.

Note for future PRs: The ObjC b2cAuthorities is a NSDictionary (policy name → authority URL), while the Swift struct models it as [String]. This will need to be reconciled in a later PR when consumers migrate. Also, b2cAuthorityForPolicy(_:tenantId:) has no Swift equivalent yet.