* add a little Stash utility.
* add radio state RAII helper.
* first part of radio_state changes
* add radio_state_ to rest of apps
* fix freq_step and format
* fix unused ui_sigfrx: corrected sample rate, added back freq setting
* Consolidate styles into a Styles class and clean up code
* Format
* Add style_bg_dark_grey for nav bar
* Fix bugs found in PR
* Rename styles
* Add bg_white style
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Co-authored-by: kallanreed <kallanreed@outlook.com>
Co-authored-by: gullradriel <3157857+gullradriel@users.noreply.github.com>