feat(s7commplus): add typed symbolic tag API

[gijzelaerr]

Closes #837

Adds a public typed symbolic catalog and name-based sync/async APIs:

• preserve access path, software/wire datatype, SymbolCRC, array dimensions, string length, and optimized/classic offsets from browse metadata
• add resolve_tag, read_tag(s), and write_tag(s) with cached catalog lifecycle
• encode writes with the resolved PValue datatype instead of BLOB
• return per-item success/error results for batch operations
• refresh and safely retry failed reads once only when a fresh browse confirms the SymbolCRC changed
• never retry writes after a potentially ambiguous transport failure
• retain all existing low-level symbolic methods

Validation:

• uv run pre-commit run --all-files
• uv run pytest -q --tb=short (2085 passed, 82 skipped)
• uv build --quiet

[gijzelaerr]

@NiklasReisser Could you give the public typed-symbolic-tag API here, plus the stacked subscription lifecycle in #891, a focused code/API review? The main questions are whether the public types and error behavior are coherent and whether the subscription lifecycle has a predictable ownership/cleanup model. Real-PLC validation is being coordinated separately.