Merge new features from `dev` branch

[TBog]

• add gradle Sha256

• add share image command

• Bump gradle wrapper from 8.0 to 8.4

• Remove unused buttons from source item layout

• add open source button

• add confirm dialog when removing subreddit

• treat API key like a password in UI

• add tooltips to open and remove buttons

• fix share image icon

• add clear cache to the sources activity

• add subreddit preview

• WIP cache comments

• show cached subreddit topics and images

• add click and long touch to preview

• make refresh work unique