[EuiMarkdownEditor] Add ability to unregister standard plugins (tooltip)

[timroes]

The EuiMarkdownEditor has currently no possibility to unregister the initial plugins (i.e. the tooltip plugin atm) when using it. Even passing in an empty array to the uiPlugins property will still cause it to be registered.

The component should let the consumer leave complete choice about what plugins will be used, and allow unregistering also that initial plugins.

[chandlerprall]

This should have been treated the same way parsingPluginList and processingPluginList:

1. default array exposed through a getter/creator function
2. accepting an override prop

[K-Kumar-01]

@chandlerprall @timroes
I have tried some code that might be able to solve the issue.
Screenshot

Here on the console panel, I logged the plugins list and it can be seen that the plugin is not there in one of the two logs
(Not used useEffect so each one is logged 2 times)
I have basically used the idea of passing an extra prop which will ensure to include or not include the plugin as required.
Can I make a PR on the issue?

[chandlerprall]

Can I make a PR on the issue?

Please do!

[K-Kumar-01]

@chandlerprall
I have made a PR
However, it says a contributor agreement. I have signed that but still, it shows that the agreement is not signed.
Can you please explain this and review my PR?

[chandlerprall]

Resolved by #4383