Trichrome is the default system Webview browser for Android. Webview is basically the browser that is built into apps that want to display a webpage. It is technically its own app but is used by other apps.
GrapheneOS does not use trichrome like most Android phones do. Instead, Vanadium is the webview browser. This is usually a good thing because it means any app displaying webpages benefits from the security of Vanadium.
If you install trichrome, it should appear as a regular app in Settings->Apps where you can remove permissions and uninstall it if you want. GrapheneOS is specifically designed to prevent apps from being deeply embedded with the system.
JayJay So my question is, if I accept and install trichrome to the work profile, will this library find it's way outside of the work profile and be accessible in the other profiles also?
If you install an app on a single profile, any other profile could use that app only if it's explicitly installed there. Other profiles will behave as though you never installed it.
JayJay If I want to get rid of all traces of this library, can I just delete the work profile and the library will be gone together with the profile also?
Apps are installed in a shared space, only app data and the list of "installed" apps is held in each profile. So there is a possibility that deleting the profile would not delete the apps, just make them unavailable. I'm not sure whether the apps' program data themselves would be deleted or not, but in any case it shouldn't affect security since it will no longer run.
Personally I would try Samsung browser if it doesn't require you to change system webview. As long as you adjust permissions on the apps and don't use that profile for anything outside of work it is secure.