Better y-axis titles when showing multiple sensors

[Flix6x]

Description

• Add support for more shared base units in y-axis titles
• Add support for shared price units, currencies, speeds and percentages
• Added changelog item in documentation/changelog.rst

Look & Feel

Before:

After (notice the y-axis title changed from Value to Temperature):

How to test

The docstrings of the new unit util functions include doctests. Doctests aren't part of the automated test suite, though, but they will be - #1347

[Flix6x]

@BelhsanHmida This is the important bit to check. The rest is of this PR comes from me merging #1347 into this PR branch, sorry.

[BelhsanHmida]

I looked into the relevant refactoring, and it looks good! I tested it, and the results are as expected. I also tested the code overall, and it works fine. However, I found cases where shared units don’t work properly (e.g., wind speed in km/h and m/h). I’m guessing these units aren’t implemented yet, but I just wanted to note this.

Here are the test results for a couple of units: Screencast from 2025-03-05 01-51-43.webm

[BelhsanHmida]

Another feature I wanted to ask about is handling sensors with the same dimension but different units—for example, one in MW and another in kW. Currently when we overlay these sensors, the Y-axis shows Value (a.u.). Should we consider standardizing the Y-axis to the smallest unit (e.g., kW in this case) for better clarity. so it would be Power (kW)?

[Flix6x]

High-quality review, thank you!!

I found cases where shared units don’t work properly (e.g., wind speed in km/h and m/h). I’m guessing these units aren’t implemented yet, but I just wanted to note this.

Good finds. For now I'll either include xfail test cases for EUR (currency) and km/h (speed) units, or implement fixes for some of these cases already.

handling sensors with the same dimension but different units—for example, one in MW and another in kW. Currently when we overlay these sensors, the Y-axis shows Value (a.u.). Should we consider standardizing the Y-axis to the smallest unit (e.g., kW in this case) for better clarity.

I don't think we should unless we also scale the MW data to kW. I'll open a new issue for this, because it would be a good feature imo. #1352