Forward scroll event from vm to parent container

[edlerd]

Done

• Forward scroll event from vm to parent container
• Fix height on vm resize to avoid scrollbars

Fixes #700

QA

1. Run the LXD-UI:
   • On the demo server via the link posted by @webteam-app below. This is only available for PRs created by collaborators of the repo. Ask @mas-who or @edlerd for access.
   • With a local copy of this branch, run as described here.
2. Perform the following QA steps:
   • Test a VM with graphic console. Scrolling when hovering the VM should also scroll the parent html container.

[webteam-app]

Demo starting at https://lxd-ui-702.demos.haus

[mas-who]

LGTM 👍