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>

tests/azure_policy_builtins/cases/date_time_add.yaml

@@ -41,25 +41,29 @@ cases:
     args: ["2024-01-15T12:00:00Z", "invalid"]
     want_undefined: true
 
+  # Input without explicit timezone is treated as UTC; outputs are
+  # normalized to ISO 8601 with an explicit timezone (`Z` for UTC).
   - note: datetime_without_timezone
     args: ["2024-01-15T12:00:00", "P1D"]
-    want: "2024-01-16T12:00:00"
+    want: "2024-01-16T12:00:00Z"
 
   - note: add_one_week
     args: ["2024-01-15T00:00:00Z", "P1W"]
     want: "2024-01-22T00:00:00Z"
 
+  # Azure Policy normalizes all output to ISO 8601 T-separated format with
+  # explicit timezone, regardless of input format.
   - note: space_separated_datetime
     args: ["2020-04-07 14:55:59", "P3D"]
-    want: "2020-04-10 14:55:59"
+    want: "2020-04-10T14:55:59Z"
 
   - note: space_separated_datetime_with_z
     args: ["2020-04-07 14:55:59Z", "P3D"]
-    want: "2020-04-10 14:55:59Z"
+    want: "2020-04-10T14:55:59Z"
 
   - note: space_separated_datetime_with_offset
     args: ["2020-04-07 14:55:59+05:30", "P1D"]
-    want: "2020-04-08 14:55:59+05:30"
+    want: "2020-04-08T14:55:59+05:30"
 
   - note: output_format_date_only
     args: ["2020-04-07T14:55:59Z", "P3Y2M", "yyyy-MM-dd"]
@@ -98,30 +102,34 @@ cases:
     args: ["2024-01-15T12:00:00+05:30", "P0D", "u"]
     want: "2024-01-15 06:30:00Z"
 
-  # Fractional seconds preservation (default round-trip, no explicit format)
+  # When no explicit output format is provided, datetime output is normalized
+  # to ISO 8601 T-separated form with timezone, regardless of input format.
+  # Explicit third-argument formats may intentionally produce other forms
+  # (for example, space-separated output). Fractional seconds are preserved
+  # when non-zero.
   - note: roundtrip_iso_no_tz_with_frac
     args: ["2024-01-15T12:00:00.123", "P0D"]
-    want: "2024-01-15T12:00:00.123"
+    want: "2024-01-15T12:00:00.123Z"
 
   - note: roundtrip_iso_no_tz_with_frac_add
     args: ["2024-01-15T12:00:00.500", "P1D"]
-    want: "2024-01-16T12:00:00.500"
+    want: "2024-01-16T12:00:00.500Z"
 
   - note: roundtrip_space_no_tz_with_frac
     args: ["2024-01-15 12:00:00.456", "P0D"]
-    want: "2024-01-15 12:00:00.456"
+    want: "2024-01-15T12:00:00.456Z"
 
   - note: roundtrip_space_z_with_frac
     args: ["2024-01-15 12:00:00.789Z", "P0D"]
-    want: "2024-01-15 12:00:00.789Z"
+    want: "2024-01-15T12:00:00.789Z"
 
   - note: roundtrip_space_offset_with_frac
     args: ["2024-01-15 12:00:00.123+05:30", "P0D"]
-    want: "2024-01-15 12:00:00.123+05:30"
+    want: "2024-01-15T12:00:00.123+05:30"
 
   - note: roundtrip_no_frac_stays_clean
     args: ["2024-01-15T12:00:00", "P0D"]
-    want: "2024-01-15T12:00:00"
+    want: "2024-01-15T12:00:00Z"
 
   - note: roundtrip_rfc3339_utc_with_frac
     args: ["2024-01-15T12:00:00.123Z", "P0D"]
@@ -137,11 +145,11 @@ cases:
 
   - note: roundtrip_rfc3339_explicit_zero_offset
     args: ["2024-01-15T12:00:00+00:00", "P0D"]
-    want: "2024-01-15T12:00:00+00:00"
+    want: "2024-01-15T12:00:00Z"
 
   - note: roundtrip_rfc3339_explicit_zero_offset_with_frac
     args: ["2024-01-15T12:00:00.500+00:00", "P0D"]
-    want: "2024-01-15T12:00:00.500+00:00"
+    want: "2024-01-15T12:00:00.500Z"
 
   # Unknown single-char format specifier is a real error
   - note: unknown_format_specifier_q