Client scripts to join group multisig rotated from kli AIDs

[pfeairheller]

This PR includes:

• Scripts to join a multisig group migrated from a multisig created with 4 KLI participants. These scripts create 4 KERIA agents each with their own Salty AID and then accepts the rotation of a mutlsig group AID adding them as the sole participants in the group multisig.
• New test script for creating 4 agents each with an AID that will become the participant in a group that is rotated to give them signing and rotation authority.

[codecov]

Codecov Report

Merging #97 (d5b7b1f) into development (6246421) will increase coverage by 1.19%.
Report is 6 commits behind head on development.
The diff coverage is 100.00%.

@@               Coverage Diff               @@
##           development      #97      +/-   ##
===============================================
+ Coverage        89.27%   90.47%   +1.19%     
===============================================
  Files               16       16              
  Lines              998     1008      +10     
===============================================
+ Hits               891      912      +21     
+ Misses             107       96      -11     

Files	Coverage Δ
src/signify/app/grouping.py	100.00% <100.00%> (+41.66%)	⬆️

... and 4 files with indirect coverage changes

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