Move Ontology Browser to Menu Bar's Tools dropdown from Tools -> More Tools

https://github.com/WormBase/website/issues/3058
Ontology Browser new svg icons for has_part and preceded_by

Previous ones didn't work on Safari.
https://github.com/WormBase/website/issues/3061
Merge pull request #3059 from WormBase/ontology_browser

Move Ontology Browser to Menu Bar's Tools dropdown from Tools -> More To...