[ML] Remove dependent sub suite structure from test files

[pheyos]

Summary

With the changes planned in #48683 test suites defined via describe should be completely independent. The current test file structure in ML tests contains sub suites that depend on each other. This PR removes those sub suites (and moves the name into each it, so the reporter output should be the same), such that all test steps that are dependent on each other are executed in one big suite.

Change details

• Removed sub suite levels (describe('job creation', function() {, same for job cloning and job deletion)
• all contained test steps (it blocks) are now contained in the main suite (e.g. describe('single metric', function() {)
• all test steps descriptions now contain the title of the removed sub suite, e.g.

  describe('job creation', function() {
      it('loads the job management page', async () => {
  

  is now

  it('job creation loads the job management page', async () => {
  

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[peteharverson]

LGTM

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: aeaf953

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 3573e7d