Make search for service flags configurable

[123BLiN]

Greetings!

First of all thanks a lot for this code!

I want to make the search=true/false configurable for the service commands
the reason is that as a user I'm lazy and just want to define some defaults globally no matter of the service or the specific command I will use.

So for example if my env var prefix is FOO I want to define the default FOO_ACCOUNTID env var and expect it propagated to all services and functions I have

I can try to create a PR but I'm not a real golang dev
wdyt?