fix(ui): Prevent link delete buttons from overlapping

[Ma77Ball]

Purpose

This pull request moves the delete button on links from the sending operator to the receiving operator to avoid overlap.

Closes #3074

Summary of Changes

• Changed link delete button from tool markup to a linktools.button
• changed the distance of the info button to -60 to start from the end of the link
• Subscribe to linkView and add info and remove button using the tools view

Demo

[Copilot]

Pull Request Overview

This pull request fixes an issue where link delete buttons were overlapping by relocating them from the sending operator to the receiving operator side of the link.

• Changed the delete button from tool markup to a proper linktools.button implementation
• Modified the info button position to start from the end of the link (distance: -60)
• Updated the link mouse enter event handler to use tools view for better button management

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
joint-ui.service.ts	Added new getRemoveButton() method and updated info button positioning
workflow-editor.component.ts	Refactored link mouse enter handler to use tools view instead of direct attribute manipulation

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[aglinxinyuan]

Please address the comments provided by Copilot and provide a new demo that addresses the following issues:

1. The resolution of the screenshot is too low.
2. The demo does not clearly show how this PR resolves the issue of multiple links having overlapping delete buttons.

[chenlica]

I added myself as a reviewer. Please do not merge it without my approval.