Add faster Truncated Normal

[rohanbabbar04]

Description

• Add TruncatedNormal with all methods.
• Add test in test_scipy.py.
• Add TruncatedNormal to docs.

Don't really know why the test_mle in preliz/tests/test_distributions.py is failing, changing it to (-np.inf,np.inf) seems to work...

Checklist

• [x] Code style is correct (follows pylint and black guidelines)
• [x] Includes new or updated tests to cover the new feature
• [x] New features are properly documented (with an example if appropriate)

[aloctavodia]

What is the error you are getting for test_mle?