Pull to refresh doesn't work when there are no tasks

[dturner]

Steps to repro:

• Load app, delete any existing tasks so that "You have no tasks!" is displayed
• swipe vertically downwards

Expected outcome

• The loading spinner is displayed

Actual outcome

• Nothing happens

Further details:

Pull to refresh is implemented in the LoadingContent composable. This either displays empty content or if it is non empty (specified by the logic tasks.isEmpty() && !loading) a container which supports pull to refresh.

So the problem is that the empty content should be displayed inside a container which supports pull to refresh.

Additionally the code is currently using SwipeRefresh from the accompanist library which is deprecated and needs migrating https://google.github.io/accompanist/swiperefresh/#migration

[AnirudhPudari]

@dturner Please review the issue as addressed here in this PR #934. Thank you

[AnirudhPudari]

@dturner @manuelvicnt @tunjid Please take a look and review this PR #934. Thank you

[dturner]

Sorry for the delay. Please fix the spotless formatting on the PR.