Kubernetes Agent access tokens: Add a name field in the token creation process

Spun out of the discussion here: #298748[001__Agent_details_page-Access_tokens_list.png] (comment 496690569)

Proposal

When the users create a token from the CLI or the UI they are required to add a name for the token. The name should follow the GitLab naming conventions for other GitLab tokens.

For existing tokens provide names automatically generated by GitLab.

• Name field
• Description field