Create a linting rule to prevent RTL breaking inline styles

[marcellamaki]

Across Kolibri, there are a number of places where we are adding static inline styles, and some of them break RTL, for example

style=margin-left: 8px;

We should both add a linting rule to prevent this in the future, as well as remediate existing instances. This issue is to address the first part, the linting.

Richard used this regex successfully in the codebase to find matches, and we can repurpose it

style="[^"]*(left|right|Left|Right)[^"]*"