Add tests for address and key

[tacmota]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 88.13%. Comparing base (d00442e) to head (18c9d6e).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
pycardano/key.py	66.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #410      +/-   ##
==========================================
+ Coverage   86.40%   88.13%   +1.72%     
==========================================
  Files          32       32              
  Lines        4201     4204       +3     
  Branches     1047     1048       +1     
==========================================
+ Hits         3630     3705      +75     
+ Misses        399      348      -51     
+ Partials      172      151      -21     

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[cffls]

LGTM, thanks!