Add ML-KEM and ML-DSA to well-known OID lookups

[vcsjones]

This adds ML-KEM and ML-DSA to the well-known OID lookup. The evidence of needing these in the well-known lookups is as such

1. the S/MIME CA/B working group approved PQC algorithms, ML-DSA and ML-KEM in ballot SMC013. Sections 7.1.3.2.4 and 7.1.3.2.5 of the requirements enable the use of these. HashML-DSA is explicitly excluded.

2. The Server Cert working group does not have as much progress here but the current draft proposal indicates ML-DSA-44 ML-DSA-87 as a start.

3. The Code Signing Working Group has largely only looked at ML-DSA-87. The most I was able to glean thus far is from their meeting minutes

   LMS was discussed but discouraged by Microsoft due to its complexity and state management challenges. SLH-DSA and hash-MLDSA were mentioned as less desirable or redundant. Microsoft confirmed support for MLDSA 87 and plans for additional parameter sets, but expressed reservations about LMS.

Given the discussion so far, I left out SLH-DSA so far as there seems to be no interest in adopting it just yet, so it doesn't need a fast path. Likewise for the HashML-DSA parameters. CompositeML-DSA may be added later as specifications ramp up and start using it, but right now it seems lacking to me.

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[Copilot]

Pull request overview

Adds additional post-quantum algorithm OIDs (ML-DSA parameter sets and ML-KEM parameter sets) to System.Formats.Asn1’s internal well-known OID tables so AsnWriter / AsnDecoder can use the fast-path mapping for these identifiers.

Changes:

• Extended WellKnownOids.GetValue / WellKnownOids.GetContents to include ML-DSA (44/65/87) and ML-KEM (512/768/1024) OIDs.
• Updated the packed data table and adjusted slice offsets to include the new entries.
• Added/extended OID reader/writer tests with the new OID values.

Show a summary per file

File	Description
src/libraries/System.Formats.Asn1/src/System/Formats/Asn1/WellKnownOids.cs	Adds ML-DSA / ML-KEM OIDs to the internal well-known mapping tables (bytes↔string) and updates slice offsets.
src/libraries/System.Formats.Asn1/tests/Writer/WriteObjectIdentifier.cs	Extends writer test data with the new OID strings and expected encodings.
src/libraries/System.Formats.Asn1/tests/Reader/ReadObjectIdentifier.cs	Adds a decoder test case set for the new OID encodings.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 1