[v4-beta user feedback] inconsistent region coordinate format (decimal vs sexagesimal) with matching FK5 vs GAL images

[kswang1029]

Describe the bug
When we have two images loaded, one as GAL (spatial matching reference) and the other as FK5, if we do not match them, in the region dialog we see consistent coordinate formats when we switch coordinate systems (ie GAL: decimal, FK5: sexagesimal). However, if we match the two images, we start to see inconsistent coordinate formats on the FK5 image where we see FK5: decimal.

To Reproduce
Steps to reproduce the behavior:

1. load a GAL image and append a FK5 image
2. match them and create a region
3. enable region dialog and set to different coordinate system to observe the format of the displayed coordinate

Expected behavior
When the coordinate systems are ICRS, FK5 and FK4, the coordinate format should be sexagesimal. For GAL and ECL, the format should be decimal.

Platform info (please complete the following information):

• OS [e.g. macOS Monterey]: macOS Ventura
• Browser [e.g. chrome, safari, electron app]: chrome
• Browser version [e.g. 22]: 114
• Backend branch [e.g. dev, v3b2 release]: dev, v4-beta
• Frontend branch [e.g. dev, v3b2 release]: dev, v4-beta

Additional context
Add any other context about the problem here.

[kswang1029]

@YuHsuan-Hwang do you have time to have a look?