[Milestone 1] Add namespace input field to CSPM and KSPM integrations

[opauloh]

Motivation

As part of adding namespace support in CSP integrations in Kibana, we need to introduce the namespace input in our CSPM and KSPM integration's custom UI.

Requirements

This should be the last task of Milestone 1 as all the necessary tasks should be in place before the option is enabled in the UI to the users.

Definition of done

• [ ] Advanced setting section is added in CSPM and KSPM integration
• [ ] Namespace input field is added to CSPM integration under advanced settings
• [ ] Namespace input field is added to KSPM integration under advanced settings
• [ ] Namespace input field has the same description and links provided in other fleet integrations
• [ ] Namespace input should validate against valid characters supported for the namespace field
• [ ] Integration should be saved with the user input namespace
• [ ] If the namespace is not set in the integration, the namespace should fallback the Agent Policy namespace (in Agent Policy advanced options)
• [ ] End-to-end test is added to test this feature.
• [ ] Once created the integration the namespace is no longer edited.

Out of scope

• Edit namespace
• Findings page, dashboard

Screenshots

Related tasks/epics

Namespace docs Epic

[elasticmachine]

Pinging @elastic/kibana-cloud-security-posture (Team:Cloud Security)