feat(azure_policy): test runner, compiler fixes, and example program (#700)

Adds the YAML test runner that exercises the companion test data PRs, plus
several compiler fixes surfaced during testing:

- Removed parameter register caching that produced wrong results inside
  short-circuiting allOf/anyOf blocks; added literal-index caching for
  parameter defaults to avoid repeated O(n) literal-table scans
- Simplified cross-resource effect details to only emit roleDefinitionIds
  and type (deployment templates are not evaluated for compliance)
- Replaced guid/uniqueString builtins with clear "unsupported" errors
- Normalized datetime output to ISO 8601 with Z suffix
- Added azure_policy parser MAX_COL constant (8192) for long template
  expressions, keeping the global DEFAULT_MAX_COL at 1024
- Added rvm to azure_policy feature dependencies since the compiler
  targets RVM bytecode

Also restructures the example binary into examples/regorus/ with new
azure-policy-eval and azure-policy-aliases subcommands, adds C# alias
normalization tests, and documents Azure Policy support in the README.

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Cargo.toml

@@ -24,7 +24,7 @@ default = ["full-opa", "arc", "rvm"]
 
 arc = []
 ast = []
-azure_policy = ["dep:jsonschema", "dep:chrono", "dep:ipnet", "dep:icu_casemap", "dep:hashbrown", "arc", "dashmap"]
+azure_policy = ["dep:jsonschema", "dep:chrono", "dep:ipnet", "dep:icu_casemap", "dep:hashbrown", "arc", "dashmap", "rvm"]
 azure-rbac = ["regex", "time", "net"]
 base64 = ["dep:data-encoding"]
 base64url = ["dep:data-encoding"]