feat: make parse_url compatible

[parthchandra]

Which issue does this PR close?

Closes #4150.

Rationale for this change

PR #4350 wired parse_url through Comet's serde layer to the upstream datafusion-spark UDFs but marked it Incompatible due to divergences between the WHATWG URL Standard (url crate) and Spark's java.net.URI (RFC 3986). This PR replaces the upstream implementation with a local RFC 3986 regex-based
parser that matches Spark's behavior, promoting parse_url from Incompatible to Compatible.

What changes are included in this PR?

New: native/spark-expr/src/url_funcs/parse_url.rs

• CometParseUrl and CometTryParseUrl UDFs using RFC 3986 Appendix B regex decomposition instead of the WHATWG url crate
• Fixes all tracked divergences from Spark:
  1. Empty-string URL with PATH/FILE now returns "" (was NULL)
  2. FILE on URL without explicit path (http://host?foo=bar) returns ?foo=bar (was /?foo=bar)
  3. PATH on trailing slash (http://host/) returns "/" (was "")
  4. 3-arg QUERY with key returns raw percent-encoded value (was decoded)
• Additional correctness fixes found during adversarial review:
  • Query values containing = (e.g., ?a=b=c) now correctly return b=c
  • 3-arg call with non-QUERY part (e.g., parse_url(url, 'HOST', 'key')) returns NULL
  • Empty port (http://host:/path) strips trailing colon
  • Empty authority (http:///path) returns NULL instead of ""
• ANSI mode: raises [INVALID_URL] error for malformed URLs (spaces, control chars, missing scheme with ://)

Modified: native/core/src/execution/jni_api.rs

• Registers CometParseUrl/CometTryParseUrl from spark-expr instead of upstream SparkParseUrl/SparkTryParseUrl

Modified: spark/.../serde/url.scala

• Removes Incompatible override and incompatibleReason (now Compatible by default)

Modified: SQL test files

• parse_url.sql: expanded from 4 fallback queries to 30+ native-execution queries covering all components, edge cases, and divergence fixes
• parse_url_ansi.sql: enables previously-ignored ANSI error tests with expect_error(INVALID_URL)

How are these changes tested?

• 25 Rust unit tests in parse_url.rs covering all URL components, divergence fixes, error handling, null propagation, and edge cases (query values with =, 3-arg non-QUERY, empty port, empty authority, IPv6, malformed URLs)
• SQL file tests (parse_url.sql, parse_url_ansi.sql) verified against Spark on both spark-4.0 and spark-4.1 profiles
• Adversarial code review identified and fixed 4 additional correctness issues before merge