chore(ui): update ansible snippet variable names (https://gitlab.com/postgres-ai/platform/-/issues/257)

Description

Related MR: dle-se-ansible!42 (merged)

Since in version 3.4.0 we renamed DLE to DBLab Engine changes were made to the variable names

1. all dle_ variables renamed to dblab_engine_
2. platform variables now without 'dle_', new names: platform_project_name, platform_org_key, platform_url

Related issue

https://gitlab.com/postgres-ai/platform/-/issues/257

Examples

Checklist

• MR description has been reviewed
• MR changes are functionally tested
• MR does NOT have API/CLI changes OR there are API/CLI changes and they have been reviewed & DOCS ARE ADJUSTED (reference doc, etc)
• MR does NOT have UI changes OR there are UI changes and they have been reviewed & UX IS REVIEWED