[Lens] Move lens enums from chrome/browser/ui/lens to components/lens

Move lens_overlay_dismissal_source.h and
lens_overlay_invocation_source.h from chrome/browser/ui/lens to
components/lens so it can be shared with iOS.

Change-Id: Id80d907939033de5ce88ebf434d4f2e8efef5ef2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5887427
Commit-Queue: Christian Xu <christianxu@chromium.org>
Commit-Queue: Radu Nitescu <radunitescu@google.com>
Reviewed-by: Radu Nitescu <radunitescu@google.com>
Auto-Submit: Christian Xu <christianxu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1359837}