Remove invalid tx hash from storage

[grarco]

Currently, for replay protection, we remove the hash of an inner transaction from storage (i.e. allow replay) when the tx goes out of gas or if the transaction is Decrypted but was rejected by process_proposal. We should do the same in more cases:

• if the inner tx turns out to be Undecryptable
• if the signature on the inner tx is invalid (needs support on the WASM side)

Also add unit tests for these cases