PA team paper cuts 17.6

What does this MR do and why?

#490934 (closed) - PA team paper cuts 17.6

Completing 4 small UX polish issues for pipeline authoring

Child issues: #492453 (closed), #485641 (closed), #488902 (closed)

Note: As I will be OOO 10/17-10/18, @sunjungp will be the DRI for this MR

Screenshots and testing instructions

Pipeline empty state button variant

Issue

#492453 (closed)

Testing Instructions

1. In a project that does not have CI set up, navigate to Build > Pipelines

Here is a patch file to force the empty state in any project: pipelines_empty_state.patch

Before	After

Scheduled pipeline button tooltip

Issue

#485641 (closed)

Testing Instructions

1. Build > Pipeline schedules
2. Schedule a pipeline with dummy data

Before	After

Variable drawer padding and scroll

Issue

#488902 (closed)

Testing Instructions

1. Project settings > CI/CD > variables
2. Click "Add variable" button to expand the drawer
3. Note that space has been increased below the buttons to 32px
4. Enter any string in "key" and click "Add variable"
5. Note that drawer scrolls to top to view alert

Before	After