gene's encode_uri added/adapted to python

[ATorrise]

What It Does

Ports the URI-encoding fixes from Gene's Zowe CLI PR zowe/zowe-cli#2758 to the Python SDK, adding EncodeUri logic

• Mirrors the 2-pathed encoding differences/strictness between uss (_encode_uri_path_for_uss) and ds(with ds being less restrictive)(_encode_uri_path_for_zos)
• Includes bug fix found when porting:
  • Console.__init__ put the literal string "defcn" (the default console name) right into the base URL, then str.replace replaced every instance of defcn in the string, so if for some reason there was a valid defcn in the URL, that would get replaced and break the URL

How to Test

Review Checklist
I certify that I have:

• updated the changelog
• manually tested my changes
• added/updated automated unit/integration tests
• created/ran system tests (provide build number if applicable)
• followed the contribution guidelines

Additional Comments

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.82%. Comparing base (91f8021) to head (ad48c77).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #408      +/-   ##
==========================================
+ Coverage   83.06%   84.82%   +1.75%     
==========================================
  Files          49       49              
  Lines        2982     3011      +29     
==========================================
+ Hits         2477     2554      +77     
+ Misses        505      457      -48     

Flag	Coverage Δ
unittests	84.82% <100.00%> (+1.75%)	⬆️

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[t1m0thyj]

Since % is included in the map of _USS_CHARS_TO_ENCODE, if a URI contains characters that are already encoded such as %20 for space, it will get converted to %2520 which is not valid.

Not sure if it's in scope to fix in this PR, given that the implementation in the Node SDK seems to have the same problem, and the input passed to this method should typically not be encoded yet. Thoughts @zFernand0 @traeok?

[traeok]

Would this mean that merging would cause a regression in behavior given the scope of expected URIs?
I think we could address this separately since the Node.js SDK already suffers from the same problem - but since we've now identified it can be an issue, maybe we can proactively add a note for developers to clarify that pre-encoded URIs are not accepted (until this is resolved).

[traeok]

Filed this as a separate issue (we can label as low priority) #413