Fix MWR Polarisation

[timhewison]

I noticed the readers for MWR on AWS (Arctic Weather Satellite) - L1B and L1C and EPS-Sterna (L1B) had the polarisation of several channels and bandwidth of 1 channel inaccurately described in the yaml files (it should be QV for all channels).

• Changed all channels to polarisation: QV (some were listed as QH)
• Changed channel 10 bandwidth to 2800 (was 2700)
• values now match those given in OSCAR: https://space.oscar.wmo.int/instruments/view/mwr_aws, https://space.oscar.wmo.int/instruments/view/mwr_sterna

I have attempted this with much helpful support on the Satpy Stack channel: https://pytroll.slack.com/archives/C0LNH7LMB/p1738314449874509

• I have not tested this, but the changes are trivial
• This is my first PR - feedback is welcome!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.11%. Comparing base (01237e2) to head (f388e6f).
Report is 58 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3045   +/-   ##
=======================================
  Coverage   96.11%   96.11%           
=======================================
  Files         383      383           
  Lines       55673    55673           
=======================================
  Hits        53511    53511           
  Misses       2162     2162           

Flag	Coverage Δ
behaviourtests	3.89% <ø> (ø)
unittests	96.21% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[coveralls]

Pull Request Test Coverage Report for Build 13076171212

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 96.222%

---

Totals
Change from base Build 12905542942:	0.0%
Covered Lines:	53758
Relevant Lines:	55869

---

💛 - Coveralls

[djhoese]

We're going to try to remake this with a separate branch. Closing...