[8.8] [SecuritySolution] Allow query when "Group By Top" field is emp…

…ty (#156968) (#157051)

# Backport

This will backport the following commits from `main` to `8.8`:
- [[SecuritySolution] Allow query when "Group By Top" field is empty
(#156968)](#156968)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Angela
Chuang","email":"6295984+angorayc@users.noreply.github.com"},"sourceCommit":{"committedDate":"2023-05-08T19:16:24Z","message":"[SecuritySolution]
Allow query when \"Group By Top\" field is empty (#156968)\n\n##
Summary\r\n\r\nFixes
https://github.com/elastic/kibana/issues/156923\r\n\r\n\r\n\r\nhttps://user-images.githubusercontent.com/6295984/236834448-74dd8a03-3d0a-4171-aa30-513244999491.mov\r\n\r\n\r\n\r\n###
Checklist\r\n\r\nDelete any items that are not applicable to this
PR.\r\n\r\n\r\n- [x] [Unit or
functional\r\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\r\nwere
updated or added to match the most common
scenarios","sha":"8b45e76d8fa526b63de6de1529cfc593ecf8723a","branchLabelMapping":{"^v8.9.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["bug","release_note:skip","Team:Threat
Hunting","Team: SecuritySolution","Team:Threat
Hunting:Explore","v8.8.0","Feature:Lens
Charts","v8.9.0"],"number":156968,"url":"https://github.com/elastic/kibana/pull/156968","mergeCommit":{"message":"[SecuritySolution]
Allow query when \"Group By Top\" field is empty (#156968)\n\n##
Summary\r\n\r\nFixes
https://github.com/elastic/kibana/issues/156923\r\n\r\n\r\n\r\nhttps://user-images.githubusercontent.com/6295984/236834448-74dd8a03-3d0a-4171-aa30-513244999491.mov\r\n\r\n\r\n\r\n###
Checklist\r\n\r\nDelete any items that are not applicable to this
PR.\r\n\r\n\r\n- [x] [Unit or
functional\r\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\r\nwere
updated or added to match the most common
scenarios","sha":"8b45e76d8fa526b63de6de1529cfc593ecf8723a"}},"sourceBranch":"main","suggestedTargetBranches":["8.8"],"targetPullRequestStates":[{"branch":"8.8","label":"v8.8.0","labelRegex":"^v(\\d+).(\\d+).\\d+$","isSourceBranch":false,"state":"NOT_CREATED"},{"branch":"main","label":"v8.9.0","labelRegex":"^v8.9.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/156968","number":156968,"mergeCommit":{"message":"[SecuritySolution]
Allow query when \"Group By Top\" field is empty (#156968)\n\n##
Summary\r\n\r\nFixes
https://github.com/elastic/kibana/issues/156923\r\n\r\n\r\n\r\nhttps://user-images.githubusercontent.com/6295984/236834448-74dd8a03-3d0a-4171-aa30-513244999491.mov\r\n\r\n\r\n\r\n###
Checklist\r\n\r\nDelete any items that are not applicable to this
PR.\r\n\r\n\r\n- [x] [Unit or
functional\r\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\r\nwere
updated or added to match the most common
scenarios","sha":"8b45e76d8fa526b63de6de1529cfc593ecf8723a"}}]}]
BACKPORT-->

Co-authored-by: Angela Chuang <6295984+angorayc@users.noreply.github.com>