Substancial UI/UX improvements

[jesusrp98]

Update specific UI elements, to improve the overall user experience. This issue is inspired by #29 and will be completed in conjunction with @deandreamatias.

• Update 'Settings' & 'About' screen, separating all list elements into categories.
• Improve contrast between navigation bar & background when dark mode is on.
• Improve 'top bar' and title legibility.
• Improve the Home screen, to better indicate what is displayed.
• Improve Home screen's list tiles, to better indicate which items can be clicked.
• Update strings that are cut in half.
• Improve Company screen legibility.
• Update 'Watch replay' icon, inside a launch's screen and roadster screen.
• Add the ability to 'minimize' a ExpandWidget.
• Update RowItem's icons & colors.
• Reduce text size (everything seems big).
• Tweak themes' colors (especially the clear theme's accent color).
• Improve HeaderMap, adding the ability to change colors based on the theme.
• Reduce padding between cards.
• Add PopupMenus to all tabs.
• Update static SpaceX photos all around the app.

This issue can be modified in the future, to include new UI improvements.
Write a comment with your own ideas & opinions!

[deandreamatias]

Massive UI/UX update