Fix code height, limit scroll to last line

[deirn]

Fixed code component height:

• Notice that the horizontal bar is not shown on files with long columns, like RegistrySynchronization. This means the component is getting cut off on the bottom. Easily can be seen on mobile version.
• Now it follows the parent height and does not use a hacky workaround.

Also limit scroll height to last line.

Demo

[modmuss50]

Great, thanks :)