Replace flot with Elastic Charts in Canvas

[timductive]

Currently, Canvas uses flot.js under the hood to power chart visualizations. We should instead use Elastic Charts.

[elasticmachine]

Pinging @elastic/kibana-canvas

[timroes]

cc @markov00

[shaunmcgough]

Are we sure we want to replace flot entirely, or do we want to just add Elastic Charts first, and then replace flot? I think it would make more sense to do two PRs for this issue. What is your thinking, @timductive and @clintandrewhall and @elastic/kibana-canvas?

[timductive]

@shaunmcgough Whenever we get to this work I think whomever picks it up should make that call.

[shaunmcgough]

Thanks, @timductive that makes a lot of sense.

[shaunmcgough]

@poffdeluxe what do you think about my comment from Sep 27, out of curiosity?

[poffdeluxe]

Since we are putting this project on hold in favor of putting Lens in Canvas, I wanted to drop my notes so far regarding my exploration of Elastic Charts: https://docs.google.com/document/d/1rti_ob-2erHO51plpvbSMrQgsB1fmQNx3JMpiU0UiXg/edit?usp=sharing

I made a branch that added a useFlot var to the plot function to let me mess around with Elastic Charts: master...poffdeluxe:poff/wip-plotting
This branch is nowhere close to production ready and needs some major clean-up

@shaunmcgough apologies for the delayed reply (just now seeing this) but yeah, I think there would absolutely have to be a transition period where people would have to opt-in to use Elastic Charts and then at some point, we would make it the default with an escape hatch to use flot