Minor fixes: typos, variable names, add comments
Simplify block and cursor implementations by adding some helper methods
Only materialize type in RunLengthEncoder when value changes
Change VARCHAR field type to VarcharType
Fix isFull calculations in BlockBuilders and BlockBuilderStatus
Remove unnecessary types field from SqlStageExecution
Only allow getLong in GroupByIdBlock
Switch to Slice murmur3 for hashes

Minor cleanups in hashes
Simplify size delta calculation in TopNOperator
Remove references to FIXED_INT_64 and VARIABLE_BINARY in messages
Move all coersion logic to FunctionRegistry
Remove unused hashSupplierClass field from JoinOperatorCacheKey
Fix timestamp type in hive connector
Rename HashJoinOperator => LookupJoinOperator
Rename JoinHash to LookupSource

This is preparation for adding index joins

Extract LookupSourceSupplier from HashSupplier
Rename HashSupplier to SettableLookupSupplier
Change position from int to long in LookupSource
Add support for index joins
Add unit tests for index joins