Make work item attribute dropdowns use same width by default

Summary

Currently work item attributes use the fluid width property in dropdowns, meaning they align to the size of the dropdown contents (up to a max width). As a result each dropdown can be a different width.

A more streamlined approach would be to prioritize having each dropdown take up the width of the sidebar (the width of the disclosure toggle), up to the max dropdown size of 456px.

Exempt widgets: This should be able to be disabled per widget, falling back to fluid width in those cases. This can allow fields that have particularly wide content to expand. Ideally all panels are at least the width of the sidebar, with select items wider.

• Parent should continue to use fluid width to allow longer titles.
• Color will need to retain fluid width for now to ensure proper formatting of the content.

Before	After

For this example the dropdown container was set to position: relative and the dropdown panel set to left: 0; right: 0