Local direct usage without cloud

[LeeTeng2001]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
Provides a golang SDK which we can directly import and use without going through network request. I've runned through the source code and found it's viable via in memory db, but currently all methods are hidden behind internal package

Describe alternatives you've considered
Nothing, I don't want t o host another permify instance just to solve this problem

Additional context

[LeeTeng2001]

I already have a working example modified from test code, can you help me skim through it and point out any error?

master...LeeTeng2001:permify:master