[Bug]: Known issue: Multiple instances of a chart cannot be rendered at once if using the Annotations plugin (Legacy)

[kidGodzilla]

Would you like to work on a fix?

• Check this if you would like to implement a PR, we are more than happy to help you go through the process.

Current and expected behavior

#818 adds specific behavior to work around the annotations plugin, that prevents multiple instances of the vue-chartjs wrapper component from being rendered at the same time, if the annotations plugin is present.

I'm testing this inside a more complex project using patch-package, another issue is that, when using the annotations, chartOptions reactivity is broken. It will always update the last instance of chart.js rendered.

Reproduction

https://codesandbox.io/s/practical-bas-2irrtp

chart.js version

v3.8.0

vue-chartjs version

v4.1.1

Possible solution

I have a PR which fixes the issue by allowing multiple instances of the chartjs component, albeit there is an opportunity to factor out some of #818 as well (remove $data._chart & all computed properties)

Reproduces the issue with annotation plugin (multiple instances): https://codesandbox.io/s/practical-bas-2irrtp

Fixes the issue with updated compiled vue-chartjs: https://codesandbox.io/s/twilight-feather-ymgud6