Z Profile: y-axis label not updated when changing units

[gica3618]

Describe the bug
When the statistic "FluxDensity" is shown in the Z Profile, changing the intensity units does rescale the y-axis, but it does not update the label of the y-axis.

To Reproduce
Steps to reproduce the behavior:

1. Open the cube member.uid___A001_X158f_X7c3.Beta_Pic_sci.spw5.cube.I.pbcor.fits from 2021.1.00485.S in the ALMA archive
2. Define a region
3. In the Z Profile window, choose FluxDensity as statistic
4. Click on the gear wheel and change the intensity units to something else, e.g. MJy/sr
5. The scale of the y-axis is updated, but the label is still showing "Value (Jy)"

Expected behavior
y-axis label should be updated to MJy in the above example

Platform info (please complete the following information):

• OS: Ubuntu 22.04.4 LTS
• Browser: Firefox
• Browser version: 123.0 (64-bit)
• CARTA version: 4.0.0