feat: pomodoro UI + general changes

- Remove settingsitem line at end
- Convert more divs to settingsitem
- Pomodoro Settings
- Add more descriptions
- Changes loaders

Co-authored-by: David Ralph <me@davidcralph.co.uk>

src/components/modals/main/settings/sections/Greeting.jsx

@@ -59,6 +59,7 @@ export default class GreetingSettings extends PureComponent {
         <SettingsItem
           title={getMessage('modals.main.settings.sections.greeting.birthday')}
           subtitle={getMessage('modals.main.settings.enabled')}
+          final={true}
         >
           <Switch
             name="birthdayenabled"