Add a typed symbolic tag catalog and read_tag/write_tag API

[gijzelaerr]

Problem

The current symbolic API requires callers to supply raw access-area IDs, LID paths, SymbolCRC values and byte payloads. Browsing can discover symbols, but there is no stable public path from a symbol name to a typed read or write.

Other active implementations provide cached symbol resolution, typed values, batch access and automatic SymbolCRC recovery.

Scope

• Introduce a public symbolic tag descriptor preserving name, access path, datatype, array metadata and SymbolCRC.
• Build a catalog from the existing browse/type-info machinery.
• Add resolve_tag, read_tag, write_tag, read_tags and write_tags.
• Encode writes according to the resolved PValue datatype instead of always using raw BLOB semantics.
• Detect SymbolCRC mismatch, invalidate the affected catalog and re-resolve once for safe read operations.
• Preserve the existing low-level symbolic methods.

Acceptance criteria

• A caller can read and write an optimized DB tag by name without manually handling LIDs.
• Scalar and array metadata survive browsing and resolution.
• Batched results retain per-item success/error information.
• Writes are never automatically retried after an ambiguous transport failure.
• Program-layout change tests demonstrate deterministic CRC invalidation and re-resolution.

Out of scope

• Subscription lifecycle
• Alarm text/catalog support (Alarm handling and subscriptions (S7CommPlus) #794)
• Persistent on-disk catalogs in the first PR