Simplify usage of credentials().issue() and ipex().grant()

[lenkan]

I am working on multisig issuance using signify and found it very hard to follow the flow for multisig issuance => grant. To get a grasp of it I cleaned up the code for issue + grant and I think I found some complicated and repeated code.

In short:

• Adding IpexGrantArgs and IssueCredentialArgs/IssueCredentialResult interfaces.
• Simplifying the flow in credentials().issue() function to avoid unnecessary re-assigning of variables and merging of objects.
• Moving the attachment creation of the embeds into ipex().grant() function to make it easier to use from a caller. This was repeated in all scripts.
• Enabling the integration tests for multisig.test.ts and credential.test.ts
• Added the "Operation" type.

I think it should be all correct since it works. I also took inspiration from the commit here pfeairheller@dc98330 to remove the redundant Saider arguments when creating the attachments.

If you do not like it, just let me know and I will close this. I don't necessarily need to get this merged. I just implemented it so that I could figure out how to do multisig credential issuance on my end and thought it was an improvement.

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (4afcb12) 81.01% compared to head (12acc53) 81.21%.

Files	Patch %	Lines
src/keri/app/credentialing.ts	94.11%	2 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff               @@
##           development     #150      +/-   ##
===============================================
+ Coverage        81.01%   81.21%   +0.20%     
===============================================
  Files               46       46              
  Lines             4187     4136      -51     
  Branches          1028     1023       -5     
===============================================
- Hits              3392     3359      -33     
+ Misses             763      745      -18     
  Partials            32       32              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[rodolfomiranda]

This is a great improvement!. You help me cross out some tasks on my todo list. The change in the ipex().grant() simplify the life of implementors.

[kentbull]

Yes, that's really good to know that you can recreate the Saider instances from the .ked attribute of an ACDC or an Anchor (anc).

[lenkan]

@rodolfomiranda @pfeairheller I have rebased this now on top of development. I rephrased the PR title to reflect the changes now that the integration test was already merged. But the PR description is still valid. Please have a look.