Flag to allow reads in local

[sirlensalot]

Allows all pact read-only db ops to be accessible in local directly without module admin.

The flag will be exposed in config in chainweb so that node operators can disable, as the performance impacts can be severe.

[emilypi]

So, to be clear, this will allow only the following if local bypass is enabled:

• read/with-read/with-default-read
• select
• keys
• txids
• txlog
• keylog

Disallowed are:

• insert
• write
• update
• create table

The way this is implemented, you'll only need 2 cases: Write vs. Reads. Will we need to expand this later? If not, we probably don't need the large enum.

[sirlensalot]

I figured explicit was better in the general case, in case we decide against some operation in the future, or allow slice-and-dice in config in the future

[emilypi]

Alright, that sounds good