"Recenter"/"reset view" button

[vogelsgesang]

Sometimes, I get lost while exploring a query plan.
A "reset view" button would be helpful in those cases

[rickcole]

It certainly would be nice to have user interface controls.
Currently, the only way to "reset view" is to reload the page, if that capability is available to the user.

[vogelsgesang]

In particular in TLV and in the JupyterLab plugin, reloading is unfortunately not an option

[vogelsgesang]

partially addressed by @luiseeo in #67
Having a "reset collapsed/expanded nodes to their original state" would still be nice to close this issue