Fix CORDEX ALADIN53 tas coordinates

[bouweandela]

Description

• Correct the coordinate system for ALADIN53 tas.
• Promote projection_x_coordinate and projection_y_coordinate from iris.coords.AuxCoord to iris.coords.DimCoords if they were demoted during load because they are not monotonic.

Closes #3105

Image with the current main branch:

Image with this branch:

Recipe to generate the above images:

documentation:
  title: |
    Example recipe that loads CORDEX-CMIP5 datasets.
  description: |
    This is an example recipe that loads CORDEX-CMIP5 datasets.
    It computes the climatology for surface air temperature (tas).
  authors:
    - loosveldt-tomas_saskia
    - andela_bouwe
  maintainer:
    - loosveldt-tomas_saskia

preprocessors:
  tas_pp:
    custom_order: true
    climate_statistics:
      period: full
      operator: mean
    mask_landsea:
      mask_out: sea

datasets:
  - dataset: ALADIN53
    driver: CNRM-CERFACS-CNRM-CM5
    ensemble: r1i1p1
    institute: CNRM
    rcm_version: v1

diagnostics:
  bias:
    variables:
      tas:
        project: CORDEX
        mip: day
        domain: EUR-11
        exp: historical
        timerange: 2003/2005
        preprocessor: tas_pp
    scripts:
      plot:
        plot_folder: '{plot_dir}'
        plot_filename: '{plot_type}_{real_name}_{alias}_{mip}'
        facet_used_for_labels: 'alias'
        script: monitor/multi_datasets.py
        plots:
          map:
            show_stats: false

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.18%. Comparing base (b03c23d) to head (7373fbd).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3110   +/-   ##
=======================================
  Coverage   96.18%   96.18%           
=======================================
  Files         271      271           
  Lines       15913    15926   +13     
=======================================
+ Hits        15306    15319   +13     
  Misses        607      607           

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