Prevent running multple BN:s and VC:s from the same data directory

[arnetheduck]

This will cause keys to be loaded by both VC and BN resulting in high slashing risk (ie the slashing DB may prevent it, but it's not certain)

This is specially true in the case of a VC and BN sharing data directory.

[cheatfate]

This is not only VC problem, it is also problem of BN itself.

[arnetheduck]

#3080 suggests one approach

It's indeed a problem both for VC:s and BN:s, though with the VC, it's very easy to put in the same data dir in the two processes by accident or misunderstanding.

[zah]

This was fixed in the v22.8.0 release through the addition of keystore locking.