Add first draft of base_jailbreak

[rmura498]

This PR introduces a first draft of a BaseJailbreakAttack abstraction.
The goal is to define a minimal, prompt-wise interface for jailbreak attacks, aligned with the existing design used for evasion attacks.

The base class provides orchestration over a list of harmful behaviors and leaves attack-specific logic, success criteria, and objectives to specific attack implementations.

[codecov]

Codecov Report

❌ Patch coverage is 95.34884% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.96%. Comparing base (9a798ff) to head (b3c57a9).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/secmlt/adv/jailbreak/base_jailbreak_attack.py	94.44%	1 Missing ⚠️
src/secmlt/tests/test_jailbreaks.py	96.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #177      +/-   ##
==========================================
+ Coverage   91.90%   91.96%   +0.06%     
==========================================
  Files          67       69       +2     
  Lines        2173     2216      +43     
==========================================
+ Hits         1997     2038      +41     
- Misses        176      178       +2     

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