Update visible plugin name to 'AI Search Flows'

[ohltyler]

Description

Updates all instances (besides the URL and certain description texts) from "OpenSearch Flow" -> "AI Search Flows". This includes the side navigation item, the breadcrumbs, the plugin title on the home page, and other various texts.

Note the underlying plugin ID remains unchanged to prevent build/registration issues with core OSD. Only user-facing changes have been changed.

Testing

• all UT passes
• all IT passes

       Spec                                              Tests  Passing  Failing  Pending  Skipped  
  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
  │ ✔  plugins/dashboards-flow-framework/c      02:43        6        6        -        -        - │
  │    reate_workflow_spec.js                                                                      │
  └────────────────────────────────────────────────────────────────────────────────────────────────┘
    ✔  All specs passed!                        02:43        6        6        -        -        -  

✨  Done in 194.81s.

• manually verified and tested basic use cases work as expected, and all visible instances of "OpenSearch Flow" have been updated accordingly. Tested for both useNewHomePage=false and useNewHomePage=true. See screenshots below.

Issues Resolved

N/A

Check List

• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.