Update StatusRoundButton colours to support a "tertiary" style (background and icon color overlay), as well as tertiary hover colour.
Fix the modal header close button so that it more closely matches the design.
Replace the buttons in the onboarding modals with StatusRoundButtons were possible.
Related to #599.
This PR is based off of #1036, which supports system colors at app startup, meaning the onboarding screens may be in dark mode, if the user has their system set to dark mode. This PR fixes the onboarding screens so they support dark mode.
It also:
1. Adds radio buttons to the `AccountList` component, as per the design
2. Adds `qsTr` where missing on the onboarding screens
3. Fixes some minor design issues
4. Updates the modals titles to match the design
5. Uses reusable Status components where possible. `EnterSeedPhraseModal` and `GenKeyModal` could have used the `StatusRoundButton` component, but there were some limitations that preventing this from being possible.
emizzle
Jonathan Rainville
Iuri Matias
