Remove old weather modules

[khassel]

The modules currentweather and weatherforecast were already only dummies displaying they are deprecated:

"This module is deprecated since release v2.15 and removed with v2.19."

So removal was announced with v2.19, time to get rid of them ...

[codecov-commenter]

Codecov Report

Merging #2914 (f23e604) into develop (e917f40) will not change coverage. The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           develop    #2914   +/-   ##
========================================
  Coverage    63.82%   63.82%           
========================================
  Files            9        9           
  Lines          293      293           
========================================
  Hits           187      187           
  Misses         106      106           

Impacted Files	Coverage Δ
modules/default/defaultmodules.js	100.00% <100.00%> (ø)

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[rejas]

I think the README of the new weather module could be adjusted too