enable keyword & null indexing support for text type

Enhance text type inside data block:

• add support for keyword (non-analyzed multi-field) indexing: enables aggregations on text fields
• add support for indexing null: documents can be searched with existing query for null values, typically used by workflow to identify missing values

added M4 label

@ethiraj Another one for M4

changed title from enable keyword indexing support for text type to enable keyword & null indexing support for text type

changed the description

CC @ethiraj @kelham @gtmurphy @njain5

pipelines are passing for this MR, we can proceed with this MR without Elastic 7 upgrade going in first.

approved this merge request

@ethiraj can you please review this include the right people to finish the merge to master ?

assigned to @ethiraj

these changes are compatible with elastic 7? This MR (!68 (merged)) will be merged into master on 23-24 Feb.

@ethiraj - can we block this MR till Tue and do it after Elastic7?

added 26 commits

• a90c2f3d...c683219c - 25 commits from branch master
• 4b068956 - rebase

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added 2 commits

• dd4fbc8f - rebase
• 23413dbe - force commit fix for compliation errors

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approved this merge request

added 40 commits

• 23413dbe...09ef494e - 38 commits from branch master
• d1f131f4 - Merge branch 'master' into enable-keyword
• c1cf23d3 - rebase

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approved this merge request

resolved all threads

approved this merge request

@ethiraj @Dmitriy_Rudko Can you please approve this to complete the merge. We have restarted the IBM test step again and we expect to pass it this time as per comments from @jingdongsun in other storage MR. Google test are still failing.

IBM is passing now. Can you please approve?

approved this merge request