chore: clean up dead code from #956 refactor

[datlechin]

Summary

Post-merge cleanup of dead code left behind by the #956 query execution refactor (PR #960).

• Removes three unreachable DynamoDB methods (executePaginatedTaggedQuery, fetchMoreScanItems, fetchMoreQueryItems) plus the private PaginationState struct and continuation-token cache that supported them. Simplifies one consumer block in generateStatements from a 14-line cache lookup to a one-liner.
• Removes 8 stale localization keys for the old Load More UI: %@ of %@%@ rows, %lld-%lld of %@ rows, %lld-%lld of %@%@ rows, %@ rows (more available), Load More, Enforce query result limit, Limit initial query results and load more on demand, Query results exceeding this limit show Load More / Fetch All buttons.

Net: 451 lines deleted, no behavior change.

Out of scope (intentional)

• Packages/TableProCore/Sources/TableProPluginKit/ (iOS package mirror) still has the old paged API. Not linked into the macOS app, only into TableProMobile.xcodeproj. Migrating the iOS PluginKit is iOS-team work; the two PluginKits will need to be unified later.

Test plan

Pure code deletion, no behavior change. Verify by build:

• xcodebuild -project TablePro.xcodeproj -scheme TablePro -configuration Debug build -skipPackagePluginValidation passes
• DynamoDB connection still works (connect, list tables, scan / query, no regression in existing pagination of fetchScanItems / fetchQueryItems)
• Settings UI still labels the row cap correctly (no missing-translation warnings from the removed catalog keys)

Verification grep

Should return zero hits in TablePro/, Plugins/, and TableProTests/:

rg -t swift "fetchFirstPage|fetchNextPage|fetchRows\(query|fetchRowCount|stripLimitOffset|limitRegex|offsetRegex|stripMSSQLOffsetFetch|stripOracleOffsetFetch|PluginPagedResult|PagedQueryResult|loadMoreOffset|loadMoreRows|enforceQueryResultLimit|queryResultLimit"
rg "Load More" --type swift