cmd/geth: add dbDeleteAll

[weiihann]

Description

This PR adds a new tool to delete all keys from the database based on a prefix.

Example

Usage: ./bsc db delete-all <prefix>

Example:

./bsc db delete-all 0x41

The code above will delete all the keys for the prefix 'A', which removes all account trie nodes in PBSS.

[zzzckck]

#2021
This proposal may effect your PR, which will move trie node into a separate database.

[weiihann]

#2021 This proposal may effect your PR, which will move trie node into a separate database.

I'll wait for it to merge and be tested first. This PR is not a priority, will convert to draft.