Add KeyNameLookupProvider to give easy read-only access to looking up token names
Hooking TokenNameLookup (formerly: KeyNameLookup) into IndexingService

o Constructed in IAGD and passed on via NeoStoreXaDataSource
o Also made available from Kernel because that is where it should live eventually
o Renaming methods to match the Kernel API naming scheme
Make IndexPopulationJob log label names and property key names instead of ids.

o Introduce LogMode utility
o Extract TokenNameLookupProvider interface from implementation
Ensure population jobs do not fail to log when token name lookup is unavailable during shutdown or recovery

o Fix LuceneIndexRecoveryIT
Add cause to logged error.
Switch to using Transactor in favor of OldTxSafeStatementExecutor
Cleaning up error handling of FlippableIndexProxy