Move and Size Head Arrow of a multi-tail arrow

[yauhen-karmyzau]

As a User, I want to move and resize the head of a multi-tail arrow so that I can accurately represent the product in my synthesis tree.

Acceptance Criteria:

1. When the user hovers over the arrow with select or arrow tools (not erase tool), the cursor should change accordingly: hover on head line - up/down arrow; hover on right point of head - left/right arrow.

2. When the user is hovering on the right corner of the head, clicking and dragging to the left or right changes the width of the head. 2.1. During and after moving, the whole arrow should be highlighted. 2.2. Dragging to the right is not limited. 2.3. Dragging to the left is limited to [minimum head length]

3. When the user is hovering over the line of the head (not the right corner), clicking and dragging up and down changes the position of the head. 3.1. During and after moving, the whole arrow should be highlighted. 3.2. The head can be moved along the spine, with one radius of the corner curve being the limitation on both sides. 3.3. Any movement above/bellow these lines results in no movement.

Selection and hover highlighting of the whole Multi-Tailed Arrow is out of scope for this task - it will be implemented here - https://github.com/epam/ketcher/issues/5057

[ivanmaslow]

Exploratory testing is completed on the RC Remote environment:

• Ketcher [Version 2.25.0-rc.1] Build at 2024-09-03; 15:37:29
• Indigo Version 1.24.0-rc.1.0-gb8f099851-x86_64-linux-gnu-11.2.1
• Windows 11 Enterprise
• Chrome Version 128.0.6613.120 (Official Build) (64-bit)

The following checks were performed, and tests are updated:

• The head arrow of Multi-Tailed Arrow added from KET file or added by Tool can be moved up and down, but not closer than 0.15 from top and bottom tails:
• The size of head arrow of Multi-Tailed Arrow added from KET file or added by Tool can be increased to right and decreased to left (0.5 from spine):
• Checks above were performed for one/several Multi-Tailed Arrows on Canvas with/without chemical elements;
• Undo/Redo actions for moving/resizing of head arrow of Multi-Tailed Arrows added by Tool or from KET file;
• Copy-Paste and Cut-Paste actions for Multi-Tailed Arrows added by Tool or from KET file after moving/resizing of head; Movement of Multi-Tailed Arrows added by Tool or from KET file after moving/resizing of head;