Add sharing button in the Me screen.

[dvdchr]

Parent issue: #16995

Implement the "Share WordPress with a friend" button in the Me screen.

Some notes:

• The screen uses ImmuTable, but the design reuses existing style (an IndicatorNavigationItemRow) which should make the effort fairly straightforward, provided Add component to handle content fetching and presentation logic #17003 is done.
• The current IndicatorNavigationItemRow is not capable to handle loading states, so some kind of loading functionality needs to be added. The other alternative is to take a look at some activity indicator rows already present in ImmuTableRows.
  • If there's no suitable existing ImmuTableRow component, then it's possible to create an IndicatorNavigationItemRow variant that shows an activity indicator for the accessory view slot.
• There might be a some small reorganizing required for the tableViewModel computed property in MeViewController since the row is only added when the feature flag is enabled.

Design