Closes #7853

Instead of applying float:right to place the buttons (span className='options') to the right, separate the buttons wrapper and the other elements, and place them with display:flex and justify-content:space-between (styles.flexJustifyBetween) . Fix #6749

Remove updateBar.less, adding notificationBar__greetingStyle to commonStyles.js

Unify the className 'primaryButton'
  - Renamed 'buttonPrimary' to 'primaryButton' on commonStyles.js and app/renderer/components/preferences/payment/*.js
  - Renamed 'primary' to 'primaryButton' on app/ledger.js

Add styles to commonStyles.js
  - notificationBar
  - notificationBar__notificationItem
    - Introduce border-box
  - notificationBar__greetingStyle
  - notificationItem__greeting
  - notificationItem__message
  - notificationItem__secondaryMessage
  - notificationItem__button

Add a style to global.js
  - 'tabsToolbarBorderColor' (unify the border color of the buttons and the tabs toolbar)
  - 'navbarMenubarMargin'

Replace 'button' with 'css(commonStyles.notificationItem__button)'
TODO: Refactor button.less to remove 'browserButton', 'whiteButton', and 'primaryButton' from notificationBar.js and updateBar.js

Change data-test-id='options' to data-test-id='notificationOptions' on notificationBar.js

Add data-test-ids to updateBar.js
  - data-test-id='updateHide'
  - data-test-id='updateDetails'
  - data-test-id='updateLater'
  - data-test-id='updateNow'

Reduce button's line-height to 1

Auditors:

Test Plan:
1. Close the browser
2. Edit <UpdateNotAvailable> to <UpdateAvailable> on updateBar.js
3. Edit ledger-state.json to display the ledger notification bar
4. Open the browser
5. Check for update...
6. Open https://browserleaks.com/geo
7. Wait until the ledger notification bar appears