Give more user-friendly feedback when we're unable to open a link

[chrisbobbe]

From beta feedback on CZO.

See screenshot there:

Implementation

We should replace that jargony "No Activity found to handle intent […]" with something comprehensible (and still accurate).

If we don't know why we failed to open the link, we should just delete that text without replacing it. If we do know the reason, we should say it, like:

No app found to open link.

We should find all codepaths where we try to open a URL and do the same for all of them.