Speed when clicking on lines to review data

[danyill]

Initial user experience indicates that this plugin is slow making the communication explorer preferable. But I like this plugin!

In my fork, I've noticed that we unnecessarily (I think) have state attributes against the mouseX, mouseY, mouseX2 and mouseY2. Allowing these to be just class variables significantly improves user responsiveness.

[danyill]

Quite a bit of caching of different types was required but a significant speed up is possible.

My plugin has diverged too far from upstream to create a clean PR anymore, alas, but it may be of interest to look at danyill@31d02e9

It may not all be necessary, it was heavily influenced by AI but large parts of it are useful at least in point to the issues but the solutions may be an anti-pattern in some cases