Add schain allocation type to SchainOptions

[badrogger]

Changes:

• Add allocation type to SchainOptions.

Performance

• No performance related changes were introduced.

Testing

• Added additional unit tests.

[codecov]

Codecov Report

Attention: Patch coverage is 96.29630% with 1 line in your changes missing coverage. Please review.

Project coverage is 91.14%. Comparing base (5762912) to head (2e2f8e1).
Report is 4 commits behind head on beta.

Files	Patch %	Lines
skale/dataclasses/schain_options.py	96.29%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             beta     #561      +/-   ##
==========================================
- Coverage   91.16%   91.14%   -0.02%     
==========================================
  Files          65       65              
  Lines        2468     2474       +6     
==========================================
+ Hits         2250     2255       +5     
- Misses        218      219       +1     

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