Homebrew backport

This PR backports some of the changes made in #2079 for the 5.0.0 formula bump

- Use the official install command for Homebrew
- Use `brew tap --repair` to fix tap symlinks
- Remove `BREW_OPTS` variable from the installation script
- Add a simple import step at the end of the OMERO installation. This should allow us to verify the import is working and that the Bio-Formats version is correctly set (see https://www.openmicroscopy.org/community/viewtopic.php?f=4&t=7409&p=13479&hilit=ilinca#p13430).