Prior to this commit, we didn't have RTL versions of our admin and plugins CSS bundles and we always served LTR versions of those bundles even when users used an RTL locale, causing admin and plugins UI elements to never look as good as when an LTR locale was used. Example of UI issues prior to this commit were: missing margins, borders on the wrong side and buttons too close to each other etc.
This commit creates an RTL version for the admin CSS bundle as well as RTL bundles for all the installed plugins and serves those RTL bundles to users/sites who use RTL locales.
We currently have some CSS rules in `common/base/rtl.scss` that were added to workaround shortcomings of the R2 gem that we used to use to generate versions of our CSS that are suitable for RTL layouts. Those workarounds are mostly duplicates of existing rules with the only difference being that they're flipped to suit RTL layouts (e.g. `padding-left` is changed to `padding-right` and vice versa).
However, we've recently replaced R2 with `rtlcss` which doesn't have those shortcomings of R2 (see f94951147e) which means those workarounds/duplicate rules need to be removed because they're getting flipped by `rltcss`, essentially reverting them to their original LTR version and causing issues with RTL layouts.
This commit removes those workarounds that are no longer needed, and cleans up the the file that contains our RTL-specific CSS.
Meta topic: https://meta.discourse.org/t/avatar-in-rtl-website-in-wrong-place/264676?u=osama.
A first step to adding automatic dark mode color scheme switching. Adds a new SCSS file at `color_definitions.scss` that serves to output all SCSS color variables as CSS custom properties. And replaces all SCSS color variables with the new CSS custom properties throughout the stylesheets.
This is an alpha feature at this point, can only be enabled via console using the `default_dark_mode_color_scheme_id` site setting.
Run `prettier --write "app/assets/stylesheets/**/*.scss" "plugins/**/*.scss"` after making sure you installed it with `yarn`
It's recommended to configure your editor to run prettier on file save.
