Reuse format and value type parsing from multi_terms in other aggs

[imotov]

In #67597 we introduced format and user value type hint parsing logic to MultiValuesSourceFieldConfig. We should see if we can use it in other aggregations as well.

Relates to #53424

[elasticmachine]

Pinging @elastic/es-analytics-geo (Team:Analytics)

[imotov]

It might easier to address this once we make sure our format is consistent in #47469.