Add the ability to annotate some certain areas of the profile

[canova]

When working and collaborating, it's very useful to annotate some certain areas and make sure that we preserve it when saved/shared. That way either we can make the collaboration easier or we can add ourselves some notes/bookmarks to make sure that we don't forget.

It looks like Chrome performance panel also recently added this feature: https://developer.chrome.com/blog/devtools-annotations
Things we can do:

• Annotate a time range
• Annotate an entry
• Add connections between entries
• Delete and hide annotations
• Save the profile with/without the annotations

It would be great to have something similar to this so we can mark some specific areas.

┆Issue is synchronized with this Jira Task