Fix empty state of IDE pipelines tab

What does this MR do and why?

This MR fixes a long standing issue with the pipelines tab of the Web IDE.

What was the problem?

For a while, the pipelines tab of the Web IDE has used ~/pipelines/components/pipelines_list/empty_state.vue for the empty state. Unfortunately, this empty_state.vue component was changed (likely in !64200 (merged)) without realizing that it broke how it was used in the Web IDE.

What's the fix?

Let's create an empty_state.vue just for the IDE which resurrects the old working empty state.

Thanks

Thanks so much @aturinske for pairing with me on this!

Screenshots or screen recordings

Before (on master)	After	After (with pipelines)
20211119_bug_ide_pipelines	20211119_fix_ide_pipelines

How to set up and validate locally

1. Start gdk
2. Visit a project with no pipelines (you might need to create a new one)
3. Visit the Web IDE and open the "pipelines tab" on the left sidebar
4. The empty state should appear
5. Clicking the button should take you to the help page

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.