isHexString(value, length?): value is `0x${string}`
Returns true if %%value%% is a valid [[HexString]].
If %%length%% is true or a //number//, it also checks that
%%value%% is a valid [[DataHexString]] of %%length%% (if a //number//)
bytes of data (e.g. 0x1234 is 2 bytes).
Returns true if %%value%% is a valid [[HexString]].
If %%length%% is
trueor a //number//, it also checks that %%value%% is a valid [[DataHexString]] of %%length%% (if a //number//) bytes of data (e.g.0x1234is 2 bytes).