[Star tree] Star tree index configuration via mappings

[bharath-techie]

Is your feature request related to a problem? Please describe

As part of this we will design the config for star tree index during index creation. The config contains list of dimensions, metrics and the star tree specific configuration. In the initial PR and milestone, only the date field and numeric fields will be supported for dimensions whereas only numeric fields will be supported for metrics.

Describe the solution you'd like

As part of #12498, we explored specifying star tree configuration as part of index settings. But later, moved to mappings as part of #14261 as this was a better fit.

Related component

Indexing:Performance

Describe alternatives you've considered

No response

Additional context

No response

[bharath-techie]

Closing this issue as changes are merged in main