refactor: Make IOKey dataclass derived from BaseKey

[kberat-synnada]

Description

Closes #116 and #118.

Checklist:

• Tests that cover the code added.
• Corresponding changes documented.
• All tests passed.
• The code linted and styled (pre-commit run --all-files has passed).

[codecov]

Codecov Report

Attention: Patch coverage is 89.18919% with 8 lines in your changes missing coverage. Please review.

Project coverage is 86.52%. Comparing base (de07573) to head (45cacb1).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
mithril/utils/dict_conversions.py	0.00%	6 Missing ⚠️
mithril/framework/common.py	88.88%	2 Missing ⚠️

@@            Coverage Diff             @@
##             main     #117      +/-   ##
==========================================
- Coverage   86.71%   86.52%   -0.19%     
==========================================
  Files          61       61              
  Lines       15616    15617       +1     
==========================================
- Hits        13541    13513      -28     
- Misses       2075     2104      +29     

Files with missing lines	Coverage Δ
mithril/framework/logical/base.py	88.01% <100.00%> (-0.03%)	⬇️
mithril/framework/logical/essential_primitives.py	99.58% <100.00%> (ø)
mithril/framework/logical/model.py	97.48% <100.00%> (-0.01%)	⬇️
mithril/framework/logical/primitive.py	95.45% <100.00%> (+0.04%)	⬆️
mithril/models/models.py	88.55% <100.00%> (ø)
mithril/models/primitives.py	97.46% <100.00%> (ø)
mithril/framework/common.py	96.45% <88.88%> (-0.11%)	⬇️
mithril/utils/dict_conversions.py	80.25% <0.00%> (-8.60%)	⬇️

[aturker-synnada]

LGTM!