[FR] Add ability to use "send-transaction" endpoint to fat-cli

[AdamSLevy]

Is your feature request related to a problem? Please describe.
Currently fat-cli only submits entries directly to the factom blockchain. It does not allow a user to make use of the "send-transaction" fatd API method.

Describe the solution you'd like
When the user does not supply an --ecadr argument to fat-cli transact ..., attempt to use the "send-transaction" end point. When the user supplies an --ecadr argument, submit the entry directly to factomd, as is currently implemented. Additionally, allow the --curl option to output the proper curl command to submit to the tx to fatd, instead of factomd, if --ecadr is not supplied.

Additional context
The changes should be made to cli/cmd/transact*.go