Apply RocksDB documentation suggestions to reduce memory usage

[ahamlat]

Apply some RocksDB documentation suggestions to reduce memory usage.

• Set format_version to 5
• set optimize_filters_for_memory to true
• Increase block size to 32K
• set cache_index_and_filter_blocks to true (this may have a big impact on performances)

Signed-off-by: Ameziane H. [email protected]

PR description

Fixed Issue(s)

Documentation

• I thought about documentation and added the doc-change-required label to this PR if
  updates are required.

Changelog

• I thought about the changelog and included a changelog update if required.

[jclapis]

Resyncing mainnet on a Rock 5B (but set the JVM heap size to 2G to emulate a Raspberry Pi), so far it's well within the limits. I'll let it run for a few days to make sure it stays around this level.

[ahamlat]

will create another PR.

[vanjan]

what's the other PR?

[ahamlat]

@vanjan : #3985