Fix MWR Polarisation

[timhewison]

Replacing PR # 3045

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 second PR - further feedback is welcome!

[coveralls]

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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%

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

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💛 - Coveralls

[adybbroe]

Many thanks for spotting and fixing this! Looks good.