[logbook] configure flex container to display entries correctly on mobile devices

[KapJI]

Proposed change

After adding seconds in logbook I noticed that log entries don't look right from the mobile browser. This happens when entry message doesn't fit one line. Then flex container tries to shrink time and icon which looks bad. This change protects width of these elements so only message itself can be shrank.

Before:

After:

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io