Move @kbn/es-query into data plugin - filters folder

[alexwizp]

Summary

Part of #42885

What was done in this PR:

• move es-query/filters into new folder
• new namespace was created for filters. Now all code related to filters located in esFilters namespace
• tests were migrated from Mocha -> Jest
• lib folder was removed, buildFilter methods were moved directly to filters

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

• This was checked for cross-browser compatibility, including a check against IE11
• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• This was checked for keyboard-only and screenreader accessibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately
• This includes a feature addition or change that requires a release note and was labeled appropriately

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 207a8f1

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: ed4e645

[lizozom]

Code looks mostly great. Haven't tested yet.

1. I see that esFilters is consumed from /siem/server. Does this mean esFilters should be a common util?
2. I'd love someone else's opinion on the esFilters name (it's fine by me, but I'm biased)

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 508585c

[ppisljar]

code LGTM

[TinaHeiligers]

Please do not merge before @Bargs has take a look.

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: d60b7a3

[lizozom]

LGTM and tested.

Lets wait for @Bargs to approve as well and go ahead and merge this.

[Bargs]

@alexwizp @lizozom Changes look good but I do have one question in regards to the nested filter PR I have open. In that PR I added helper functions to each filter type's TS file for getting the target field from the filter (example). I then use those helpers inside a new file in the es_query directory. Since this PR makes the code in the filters directory inaccessible from the package, how should I change my code to make it work after this PR is merged? Should I just put the field finding helpers in the utils/filters.js file for the time being, as was done for a few other helpers that needed to be used in both places (at least that's my understanding of that file from looking at the changes)?

If we can answer that one question, I'm cool with merging this PR 👍

[lizozom]

@Bargs IMO you are right about putting them, temporarily, inside the utils folder.
Lets wait until @alexwizp is online tomorrow to confirm.

[alexwizp]

@Bargs yes, you can temporary put your methods into filters/utils folder. Also next week we are going to move kuery and es-query folders into new platform. If you can wait with your PR for 1 week it will be great.