Harden untrusted genesis file consumption

[ryoqun]

Problem

Like #7167, as HTTP/GET-ed genesis files can not be trusted, its deserialization and handling should be hardened. At least, before genesis hash check is done.

TBD

Proposed Solution

Just redo similar measured as #7167?

TBD

[ryoqun]

As guessed this will happen someday, this became a real issue now: #8427

[ryoqun]

Also, like this #7167 (comment), we're currently challenged to sanitize bunch of rocksdb binary files which cannot be trusted at all and can be tampered in any arbitrary way. I'll suspect rocksdb are prepared to combat off that attack surface. So, we're forced to transition to some DDL emitter for genesis instead of carrying a tiny rocksdb instance or completely outplace it. :)

[mvines]

I'd like to remove (more practically just ignore rocksdb/) in genesis entirely. It's superfluous, genesis.bin is all that matters.