incorrect trimmed velocity header of ATCA FITS images

[TienHao]

Describe the bug
This is related to CARTAvis/carta-frontend#2357.
The frontend receives incorrect headers of velocity(CTYPE3) from ATCA FITS images.
The original value of CTYPE3 in the FITS headers is 'VELO-XXX' (eg. VELO-HEL, VELO-LSR), but the OpenFileAck message shows 'VELO' in that key..

VELO-HEL turns to VELO

VELO-LSR turns to VELO

To Reproduce

1. download the test images here:
   https://drive.google.com/file/d/1MrseMvR3j9YVeLk_4bwCmDjvIaPHUtye/view?usp=sharing (CTYPE3 = 'VELO-HEL')
   https://drive.google.com/file/d/1ynmyPlgEJolb_1D8m5tWNapXIGMwmUHO/view?usp=sharing (CTYPE3 = 'VELO-LSR')

2. load it and check the log of OpenFileAck(or File header), and we will see the incorrect header.

Expected behavior
The CTYPE3 in the OpenFileAck message should be the same as the one in the FITS header.

Screenshots or videos
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Platform info (please complete the following information):

• OS [e.g. macOS Monterey]: macOS Sonoma
• Browser [e.g. chrome, safari, electron app]: Chrome
• Browser version [e.g. 22]: 124
• Backend branch [e.g. dev, v3b2 release]: dev
• Frontend branch [e.g. dev, v3b2 release]: dev

Additional context
Add any other context about the problem here.