allow self-connected agent to issue credentials, present proof

[sklump]

The v0.1 approach of selecting model record by initiator tag (filter) would not fly for v1.0 (issue-credential, present-proof) protocols: either side may initiate. Instead, select by connection identifier, available from the request context.

While altering manager.py for both, get message data from context where possible (i.e., unless routes.py instantiates and calls manager without the request context that corresponding handlers have).

Signed-off-by: sklump srklump@hotmail.com

[codecov-io]

Codecov Report

Merging #179 into master will decrease coverage by 0.05%.
The diff coverage is 23.8%.

@@            Coverage Diff             @@
##           master     #179      +/-   ##
==========================================
- Coverage   71.73%   71.67%   -0.06%     
==========================================
  Files         217      217              
  Lines        9820     9826       +6     
==========================================
- Hits         7044     7043       -1     
- Misses       2776     2783       +7