msg_processor should not fail for 'invalid' message

[noel2004]

Current msg_processor would throw assert failure when receive some message it consider as invalid (or not consistent) like:

1. A registry message specify an account id which has been used (line 39 @ msg_processor.rs)

2. The balance reported by matching engine is not consistent with the balance which manager has maintained (line 80 @ msg_processor.rs)

Such failure can be easily triggered if we run tick.ts multiple times and then handle the messages generated by matching engine. Because the reset in tick.ts 1. re-registry accounts 2. clear the balance data in matching engine

[noel2004]

To summary: all the instance should be consistent with the state in L2 blocks, so it is matching engine (and all other module except rollup manager itself)'s responsibility to correct or sync the balance data any time an inconsistent occurs.