Proposal/clear link tool state

[akulistus]

Fixes issue (#2979 (comment)) preventing text unlinking by clicking link popover item block in toolbar. Also improves the link tool’s behavior when switching between tools in the toolbar

[neSpecc]

Ideally, link tool should not know about Popover and its implementation. Explain, why it is needed.

[neSpecc]

Describe the use case please.

[neSpecc]

same here

[akulistus]

We need a way to restore the initial selection when a different popover item is clicked. Previously, this was handled by calling handleClick on nestedPopoverTriggerItem, but that approach caused linked text to become unlinked:

editor.js/src/components/utils/popover/popover-inline.ts

Lines 166 to 181 in 4ea9eb3

	protected override handleItemClick(item: PopoverItem): void {
	if (item !== this.nestedPopoverTriggerItem) {
	/**
	* In case tool had special handling for toggling button (like link tool which modifies selection)
	* we need to call handleClick on nested popover trigger item
	*/
	this.nestedPopoverTriggerItem?.handleClick();
	/**
	* Then close the nested popover
	*/
	super.destroyNestedPopoverIfExists();
	}
	super.handleItemClick(item);
	}

I see three possible approaches to implement this:

1. Current approach: detect whether a new selection occurs within the toolbar (on another element), and restore either the initial selection or the new one accordingly.
2. Introduce a new method (e.g., handleItemChange) that triggers a dedicated function inside the inline-link tool to restore the initial selection.
3. Pass a flag to distinguish between user-initiated clicks and programmatic ones, and handle selection restoration based on that context.