EuiTable: add ability to set default selected checkboxes for tables with selection

[alvarezmelissa87]

Related issue: #1077

This is an enhancement request for table components (Basic and InMemory, primarily).

It would be useful when implementing selection to be able to set a default for checkboxes that should be selected/checked by default.

Example use case:

If this table is used as part of a wizard and the user wants to go back to the step with the table once they've moved on, there's no way to retain previous selection while also allowing those selections to still be edited.

[ashikmeerankutty]

@cchaos @alvarezmelissa87 I would like to work on this.

[chandlerprall]

@ashikmeerankutty please do!

Make sure to read through the related issue #1077 , ideally we arrive at a consolidated way to set an initial set of selection values and a good way to update them after mount. The table code gets messy quickly, don't hesitate to ask questions as you dig through the components!

[ashikmeerankutty]

@chandlerprall This issue is fixed and can be closed 👍

[chandlerprall]

Closed by #3418