Rename fixed_lim to xy_lim

[aleicazatti]

Description

• Rename fixed_lim parameter to the more suitable name xy_lim in plot_interactive method.
• Add a FutureWarning.
• Fix typo in docstring.

Checklist

• Code style is correct (follows pylint and black guidelines)

[codecov-commenter]

Codecov Report

Merging #245 (a31ecf4) into main (d49d721) will increase coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #245      +/-   ##
==========================================
+ Coverage   82.81%   82.87%   +0.05%     
==========================================
  Files          29       29              
  Lines        3731     3737       +6     
==========================================
+ Hits         3090     3097       +7     
+ Misses        641      640       -1     

Impacted Files	Coverage Δ
preliz/tests/test_maxent.py	100.00% <ø> (ø)
preliz/tests/test_quartile.py	100.00% <ø> (ø)
preliz/distributions/distributions.py	91.51% <100.00%> (+0.21%)	⬆️
preliz/internal/optimization.py	100.00% <100.00%> (+0.63%)	⬆️