[Index Management][Mappings Editor] Add mappings parameters for dimensions and metrics

[yuliacech]

Elasticsearch will be adding new mappings parameters for dimensions and metrics (#74014)

Most systems will have index templates installed by a Fleet agent (when setting up data ingestion). Those index templates will have the new dimensions/metrics mapping parameters defined. So we need a way for users to add / edit the new mappings parameters, but most users are not expected to be working with this parameters directly.

Related work: issue about working with pre-installed index templates since these new mapping parameters will be added to 'managed' index templates, for example 'metrics'.

[elasticmachine]

Pinging @elastic/kibana-stack-management (Team:Stack Management)

[Dosant]

In #139922 we allowed new time series-related properties to be loaded using JSON editor.
But ideally, we need to allow editing those using UI forms. I think we can keep this issue open for this.

Also, we should add support for aggregate metric field type