ui: offroad experimental mode button (#26498)

* draft

* draft

* before qpushbutton

* icon, clean up button, clicked goes to toggles

* fix icon

* add imgs

* img

* make square

* works with layouts!

* fix gradient

* this looks good

* clean up

* clean up

* remove padding around couch

* use scene's experimental_model, new onroad design

* rename widget

* def want 3

* update translations

* add img

* add 25px of padding!

* make 300px (no change)

* clean up old images

* 5 px smaller

* add white img

* fix from merge

* no style sheets

* see how this looks on device

* aliased vertical line (clean up)

* clean up

* imgs

* couch

* delete

* bye bye

* expand toggle support

* clean up

* fix dynamic icon

* make exp icon dynamic

* order

* move to offroad

selfdrive/ui/SConscript

@@ -58,7 +58,7 @@ qt_env.Program("qt/spinner", ["qt/spinner.cc"], LIBS=qt_libs)
 qt_src = ["main.cc", "qt/sidebar.cc", "qt/onroad.cc", "qt/body.cc",
           "qt/window.cc", "qt/home.cc", "qt/offroad/settings.cc",
           "qt/offroad/software_settings.cc", "qt/offroad/onboarding.cc",
-          "qt/offroad/driverview.cc"]
+          "qt/offroad/driverview.cc", "qt/offroad/experimental_mode.cc"]
 qt_env.Program("_ui", qt_src + [asset_obj], LIBS=qt_libs)
 if GetOption('test'):
   qt_src.remove("main.cc")  # replaced by test_runner