stagedsync: polygon sync stage progress updates

[taratorio]

While testing the new polygon sync stage I found several places that needed improvements:

• for the polygon sync loop the stages.BlockHashes is not necessary since when we call polygonSyncStageService.handleInsertBlocks we perform rawdb.WriteHeader which persists the Block Hash-> Block Number mapping in the HeaderNumber table (which is what the BlockHashes stage does)
• we weren't updating the stages.Headers, stages.Bodies, stages.BlockHashes progress in polygonSyncStageService.handleUpdateForkChoice and we should since some of the stages after PolygonSyncStage are using these progresses - this is now added in this PR (similar to how it is done in the execution engine)
• switched to using rawdb.WriteHeadHeaderHash and rawdb.ReadHeadHeaderHash for getting the latest downloaded block instead of previous approach which was to save this info in SyncStageProgress table under PolygonSync_hash key

[battlmonstr]

👍