Support sanitization of block based table options

[udi-speedb]

As part of #488 there was a need to sanitize a block based table option (specifically, the optimize_filters_for_memory). In addition, the flag should be sanitized only in a specific plug-in (Speedb's paired bloom filter). The current sanitization mechanism doesn't include proper support for this.

[mrambacher]

This issue would be addressed by RocksDB #9552