Align output of the TableAgent and the SQLAgent

[philippjfr]

• Ensures that the output of the TableAgent and SQLAgent are handled the same way
• Remove the hardcoded instruction to add LIMIT to the SQL query and instead add a SQLLimit transform which can be toggled in the UI
• Cache the SQL output

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 33 lines in your changes missing coverage. Please review.

Project coverage is 56.66%. Comparing base (eb31bc8) to head (3e98518).
Report is 1 commits behind head on main.

Files	Patch %	Lines
lumen/ai/views.py	0.00%	30 Missing ⚠️
lumen/ai/agents.py	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #687      +/-   ##
==========================================
- Coverage   56.69%   56.66%   -0.03%     
==========================================
  Files          98       98              
  Lines       11677    11682       +5     
==========================================
  Hits         6620     6620              
- Misses       5057     5062       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.