Upsell the GitLab Managed Terraform state if the repo contains `.tf` files

What does this MR do?

This MR adds a banner to the top of the GitLab project page in such cases:

• the repository contains .tf files - repository_languages helper that returns the top 5 repo languages is used, so HCL files (that are used most of the time for Terraform) should be in the top 5 to enable the banner.
• there are no GitLab Managed Terraform states already used for the project.

The primary button should lead to GitLab managed Terraform State docs page. The click event on the close button should be stored in the cookies per the project to ensure that the banner won't show up again for the same user and project after being dismissed.

Screenshots or Screencasts (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• [-] I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• [-] I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Related to #330592 (closed)