Ignore webextensions functions

Moved from https://bugzilla.mozilla.org/show_bug.cgi?id=1810084:

> User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/110.0
>
> Steps to reproduce:
>
> I opened the devtools on my website (which is more a webapp than a site, as it relies heavily on JS and DOM updates) then the profiler with the "Webdevelopment" parameter. Then in the tracks I unselect everything that is not my website (parent, screenshots, others tabs or iframes).
>
> I want to focus on what I can fix to improve the performances, meaning on the code I own, not webextensions or devtools.
>
> I take a look at the flame chart mainly then the stacks.
>
> Actual results:
>
> In the flame chart, "resource://gre/modules/Timer.sys.mjs" takes 5.1% of the time.
> The MutationCallback around 2% (Lastpass, KeepInTab, uBlock origin extensions)…
>
> This is an example and the values can vary and be higher.
>
> To ignore those (I want to focus on my code) I ignore them through click + "D" or right-click -> ignore samples with this function.
>
> In the call tree they (webextensions, not devtools) are also easy to spot sicne they a little puzzle icon.
>
> Expected results:
>
> If there was either a parameter before the recording, or a button after to filter all the extensions and devtools resources, it would be great and improve my experience a lot.
>

cc nicofrand

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-606)