[curweather] x() no longer used and more (#669)

[curweather] x() no longer used and more (#669)

* [curweather] Fixes/rewrites:
- Added `App` as type-hint for $a and no & (call-by-reference) anymore
- use empty() instead of deprecated x()
- opening curly brace belongs into new line after function/method declaration
- added a lot other curly braces for better readability
- added spaces and empty lines

* [curweather] CR request:
- added/removed spaces
- added missing line-feed after opening curly brace

* [curweather] Another new line-feed added

* [curweather] CR request:
- added/removed extra spaces
- removed trailing spaces
- nicely indented code block with `'$foo' => 'bar'`

* [curweather] CR request:
- removed stray space