Add plot_interactive to Dirichlet

[rohanbabbar04]

Issue #225

Description

• Added xy_lim to plot_dirichlet
• Added plot_interactive to Dirichlet where xy_lim defines x and y for each subplot.
• Added test_plot_interactive_dirichlet for the tests.
• Added marginals checkbox when kind=pdf (for other representations checkbox is not present)

Checklist

• Code style is correct (follows pylint and black guidelines)
• Includes new or updated tests to cover the new feature
• New features are properly documented (with an example if appropriate)
• Widget states have been properly saved (only for notebooks with widgets) see for details.

A pic for pdf

[aloctavodia]

nitpick: When referencing and issue from a PR use one of these words https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword then when the PR get merged the issue will be automatically closed

[rohanbabbar04]

nitpick: When referencing and issue from a PR use one of these words https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword then when the PR get merged the issue will be automatically closed

The issue actually has 2 parts
The first one is Dirichlet the next one is MVNormal
So I just needed to mention the issue and not close it...