Indicate applied and partially applied relations for multi-selection

[aditya1010-max]

When multiple entities are selected, the raw membership editor now indicates
whether a relation applies to all selected entities or only a subset.

• Shows “Applied" when a relation includes all selected entities
• Shows “Partially Applied” when a relation includes some of them
• Preserves existing behavior for single selection

This PR addresses one aspect of issue #10981

[tordans]

@aditya1010-max before look into this…

• remember to use let/const for new code
• UI: add (a) space between word
• UI suggestion: I suggest to move the new feature to a pill/badge like look to the right of the line https://tailwindcss.com/plus/ui-blocks/application-ui/elements/badges
• please explain why this is a draft and what you plan to do before un-drafting
• please move the relevant parts of your comment on the issue here; we want the conversation about the implementation in one place (here); not scattered on issue and PR

UI:
I wonder if we want this red-green look here. Its more of a "warning", "all good" signal where this information is more of an FYI, right? We could make both just a gray FYI label… – Lets see what others say.

[tordans]

Dont quite see the value in having this extracted and then only used once.

Suggested change

	var count = relationCounts.get(entity.id) || 0;
	var flags = {
	isCommon: count === selectedEntities.length,
	isPartial: count > 0 && count < selectedEntities.length
	};
	result.push({
	relation: entity,
	value,
	display: baseDisplayLabel(entity)
	display: baseDisplayLabel(entity, flags),
	title: value,
	isCommon: flags.isCommon,
	isPartial: flags.isPartial
	const count = relationCounts.get(entity.id) || 0;
	result.push({
	relation: entity,
	value,
	display: baseDisplayLabel(entity, flags),
	title: value,
	isCommon: count === selectedEntities.length,
	isPartial: count > 0 && count < selectedEntities.length