remotes: Adds `repoLast` template parameter.

[lilliputten]

Adds repoLast template parameter for gitlens.remotes.urls settings.

Description

Allows to use the template parameter "repoLast" to substitute the last part of the URLs of the multicomponent repository path (for example, if you need to specify only the "my-repo" part from "space/project/my-repo"; in our case, in JetBrains Space).

Example for gitlens.remotes.urls.commit: https://my.company.com/p/project/repositories/${repoLast}/commits?commits=${id}.

Checklist

• [x] I have followed the guidelines in the Contributing document
• [x] My changes follow the coding style of this project
• [ ] My changes build without any errors or warnings
• [x] My changes have been formatted and linted
• [x] My changes include any required corresponding changes to the documentation
• [ ] My changes have been rebased and squashed to the minimal number (typically 1) of relevant commits
• [ ] My changes have a descriptive commit message with a short title, including a Fixes $XXX - or Closes #XXX - prefix to auto-close the issue that your PR addresses