Review GitLab Duo entitlement statements in the editor extensions

I spoke with @jglassman1 just now about his work in https://gitlab.com/gitlab-org/technical-writing/team-tasks/-/issues/1300+. Separately, I was reviewing an unrelated merge request (gitlab-org/editor-extensions/gitlab-jetbrains-plugin!1704 (merged)) and realized — wait — there are ALSO mentions of entitlements in the extensions themselves. Meaning, OUTSIDE of documentation files.

Example from the JetBrains extension, in src/main/resources/messages/GitLabBundle.properties:

duo-chat.not-licensed=GitLab Duo Chat is a paid feature, part of GitLab Duo Pro. For access, contact your GitLab administrator.
code-suggestions.not-licensed=Code Suggestions is now a paid feature, part of GitLab Duo Pro. To upgrade, contact your GitLab administrator.

What needs doing

• Review each of the extensions, glab, and the Language Server.
• Search for any mentions of Duo Pro and paid.
• Propose rewrites to the text that, at a minimum, update the language to current truth.
• Better yet, let's assume these entitlements will change again in the future. Rewrite the language to stop citing the availability in each app, and instead point to the SSOT, which is https://docs.gitlab.com/user/gitlab_duo/#summary-of-gitlab-duo-features

Tracking

• CLI (no changes needed)
• Language Server gitlab-org/editor-extensions/gitlab-lsp!1710 (merged)
• Eclipse (no changes needed)
• JetBrains gitlab-org/editor-extensions/gitlab-jetbrains-plugin!1707 (merged)
• Neovim
• VS Code gitlab-org/gitlab-vscode-extension!2607 (merged)
• Visual Studio gitlab-org/editor-extensions/gitlab-visual-studio-extension!220 (merged)

cc @scawood for shadowing purposes!