PLU-237: chore: add variable list ui dropdown enhancement

[m0nggh]

Problem

The current variable list dropdown is still using MUI components and does not follow OGP DS styles.

Solution

• Migrate to chakra components and follow ogp ds styles.
• Remove the expand and collapse list functionality because it was redundant since it is already a scroll component
• TestResult is also updated accordingly

Tests

• Check that old pipes still can input variables and execute successfully
• Check that new pipes can input variables and execute successfully
• Check that no variables appear after an empty webhook submission is made

Screenshots

Before

SuggestionPopper

Test Result

After

SuggestionPopper

Screen.Recording.2024-05-09.at.10.40.14.AM.mov

Test Result

Screen.Recording.2024-05-09.at.10.51.30.AM.mov

[linear]

PLU-237 Dropdown UI Fix

[ogp-weeloong]

Generally LGTM except the VariablesList height - if we leave at 256px, then test step with very few variables look really weird.