Improve bundle-extension range detection

As in title. We currently give a warning when the bundles extension version is in the default range of `[1.x, 2.0)` but we should also account for cases when the customer is pinned to a specific V1 version.

Start by locating the warning that checks whether the bundles extension is in the default [1.x, 2.0) range, then inspect how pinned extension versions are parsed. Done means the warning also correctly accounts for customers pinned to a specific V1 version; verify the existing behavior and add coverage for that case.

Written by the indexing model from the issue text.