Add RTL support to django-admin-style modal

[sakhawy]

Description

The django-admin-style modal has elements floating in the wrong direction for RTL

Steps to reproduce

• Create a page and add a plugin (e.g. Accordion)

Expected behaviour

• For the RTL direction, the modal's elements should be located in the proper direction and should have the expected margins, and paddings.

Actual behaviour

As per the screenshots

Screenshots

Additional information

• djangocms-admin-style==3.2.7

Do you want to help fix this issue?

• [x] Yes, I want to help fix this issue and I will join #workgroup-pr-review on Slack to confirm with the community that a PR is welcome.
• [ ] No, I only want to report the issue.