Attempt to better communicate the Hook intent.

Prior to making the asynchronous request to the host app across the
bridge, it is a better UX to presume network connectivity is present
rather than displaying network connectivity messages briefly.

Hoist the `OfflineStatus` indicator from the block list to the editor.
The block list is leveraged for inner blocks, which means it rendered
nested `OfflineStatus` indicators for blocks with inner blocks.

Additionally, the `editor` package feels like an appropriate location
for the offline detection component.

This was renamed in a commit onto which this branch was rebased.

Place non-React component exports in a separate module to enable Fast
Refresh of the React component.

Match the latest design comps.

Replace early return with logic mirroring the rest of the switch case
statements. While I suppose it could be considered subjective, it is
odd and confusing that one of the three cases was structured
differently.

Place non-React component exports in a separate module to enable Fast
Refresh of the React component.

I believe this logic erroneously prevented the spinner progress bar from
displaying when an image is successfully uploading. I.e., the logic read
"if show spinner and online, apply 'progress bar hidden' styles." I
imagine this confusion is a result of the previous logic using the `||`
pattern to conditionally apply the hidden styles, which is confusing
in itself.

This logic should likely be implemented by the way the host app
communicates the upload state. Implementing this in the JavaScript logic
is confusing or misleading, in my opinion. It adds a new, somewhat
surprising interpretation of the existing states provided by the host
app.

This allows sizing the icon for different contexts.

Update iconography and messaging when offline or or there is a upload
error.

Relying upon the network connection status alone results in the error
message erroneously changing whenever a network connection is
re-established. The error message, in fact, is a state communicated from
the host app's attempt to upload media. Therefore, this creates a new
pause state to represent uploads paused while offline.

…ubscription

The planned scope of the project was to improve the upload experience of
the Image block, as it is the most frequently used media block type.
Support for additional block types could be added at a later time.

Because the Media and Text block type relies upon a nested Image block,
it makes sense to enable the paused media uploads for a consistent UX.

If the upload state and progress is identical, there should be no reason
to invoke callbacks, update component state, or re-render.

Enables the Android host app to mirror the functionality of iOS.

…media-upload-progress-connection-subscription