Add data-content attribute to `.multi-select-pill`

Feature requests
1

Use case or problem

It is currently not possible to have colored mutli-select pills. Adding a method for snippets or themes to select multi-select pills based on their content could fix this issue.

Proposed solution

By adding a new data attribute to the .multi-select-pill element, it would be possible for snippets to style multi-select pills based on their content. For example:

.metadata-property-value .multi-select-pill[data-content="Completed"] {
	--pill-background: var(--color-blue);
	--pill-background-hover: var(--color-blue);
}

.metadata-property-value .multi-select-pill[data-content="In Progress"] {
	--pill-background: var(--color-green);
	--pill-background-hover: var(--color-green);
}