[MD] Index pattern selector which was used in maps dashboard plugin and visualization should show data source name as prefix

[BionIT]

Is your feature request related to a problem? Please describe.

I feel confused when multiple data source is enabled, while using visualization and need to select an index pattern created from connected data sources, it is almost impossible to distinguish which data source the index pattern belongs to

Describe the solution you'd like

I would want to be able to have the data source connection name as a prefix to the index pattern name, similar to what we have in saved objects page and discover data picker

saved objects page

Describe alternatives you've considered
There is no alternative other than guessing which data source the index pattern belongs to

Additional context

Add any other context or screenshots about the feature request here.

[BionIT]

Synced with @kgcreative , and please correct me if it is wrong, the prefix should be like <datasource_name>::<index_pattern_name>

[BionIT]

Happy to work on this

[BionIT]

@kgcreative This is what I have for now and should be able to raise PR by end of day if this looks good

[kgcreative]

Thank you @BionIT! This LGTM!

[seraphjiang]

Synced with @kgcreative , and please correct me if it is wrong, the prefix should be like <connection_name>::<index_pattern_name>

Sorry for nitpicking, @BionIT @kgcreative

Could we use datasourcename as right term

To be consist with design and other related doc

#1388

https://docs.aws.amazon.com/opensearch-service/latest/developerguide/direct-query-s3-configure.html

[BionIT]

Thanks @seraphjiang ! Updated the term in my comment