[Security Solutions] Show popovers inside modals

[cnasikas]

Summary

This PR fixes an issue where popovers, like pagination or filters, inside a modal, are being hidden. With this fix, only draggable popovers are being hidden.

To test it:

1. Go to Hosts -> All hosts.
2. Hover over a hostname.
3. Chose the Show top host.name menu action.
4. Click the inspect button in the Top N popover.

Expected behavior: The Top N popover is hidden while the inspect modal is displayed.

1. Open timeline.
2. Give it a name.
3. Press the gear button.
4. Press Add timeline to existing case...
5. Click the Reporters, Tags and pagination filters

Expected behavior: The popovers should be visible.

Checklist

• This renders correctly on smaller devices using a responsive layout. (You can test this in your browser
• This was checked for cross-browser compatibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately

[elasticmachine]

Pinging @elastic/siem (Team:SIEM)

[stephmilovic]

Code review looks good. I did the requested manual tests and both behave as expected. LGTM!

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 0bf9e06

Build metrics

async chunks size

id	value	diff	baseline
securitySolution	7.3MB	+78.0B	7.3MB

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[rylnd]

Tested this with both the provided instructions and against the value lists modal. Modals/popovers look good in both those cases!

[elasticmachine]

Pinging @elastic/security-solution (Team: SecuritySolution)