TermsAggregationExecutionHint missing options

[pickypg]

The existing TermsAggregationExecutionHints do not match those currently available.

ES:

• 1.0
• 1.1
• 1.2 (new options added)
• 1.3 (ordinals removed)
• 1.4
• 1.x
• master

Existing in TermsAggregationExecutionHint (from 1.0 - 1.1):

• map
• ordinals (removed in 1.3)

Expected in 1.3+:

• map
• global_ordinals
• global_ordinals_low_cardinality
• global_ordinals_hash

[gmarz]

Thanks @pickypg