Further improvement of PageStorgae V3

Enhancement

We release storage.format_version = 4 and enable PageStorage V3 by default in the v6.1 https://github.com/pingcap/tiflash/issues/3594. There are some improvements remain. Here is the tracking issue of all improvements.

• Polish the debugging tools
  • Make it a subcommand of tiflash binary
  • Make it can dump the encrypted data https://github.com/pingcap/tiflash/issues/4962
  • https://github.com/pingcap/tiflash/issues/5122
• https://github.com/pingcap/tiflash/issues/5336
• Polish the performance testing tools
  • Make it a subcommand of tiflash binary https://github.com/pingcap/tiflash/issues/5037
• #5558
• #6056
• [P2] Optimize the restore speed https://github.com/pingcap/tiflash/issues/4914
• [P2] Compression on serialized entries (in WAL), which can optimize the serialized data length for wide tables https://github.com/pingcap/tiflash/issues/4996
• [P2] https://github.com/pingcap/tiflash/issues/5078
• [P3] Split the pipeline of persisting write batch into smaller parts and speed up the throughput for WALStore
• [P3] https://github.com/pingcap/tiflash/issues/4562
• https://github.com/pingcap/tiflash/issues/5675
• https://github.com/pingcap/tiflash/issues/5700
• https://github.com/pingcap/tiflash/issues/5568
• https://github.com/pingcap/tiflash/issues/6071
• https://github.com/pingcap/tiflash/issues/6162

This is a tracking issue for remaining PageStorage V3 improvements rather than a single scoped change. Review the unchecked linked issues and the listed WALStore, compression, pipeline, and other improvement descriptions; the tracking work is done when the remaining items are addressed and marked complete.