Order recipe output in index.html

[bouweandela]

Description

This pull request updates how the index.html file is written during a run:

• the order of diagnostics from the recipe is preserved
• the output files of diagnostic scripts are sorted alphabetically

As requested in ESMValGroup/ESMValTool#3015 (reply in thread)

---

Before you get started

• ☝ Create an issue to discuss what you are going to do

Checklist

It is the responsibility of the author to make sure the pull request is ready to review. The icons indicate whether the item will be subject to the 🛠 Technical or 🧪 Scientific review.

• 🧪 The new functionality is relevant and scientifically sound
• 🛠 This pull request has a descriptive title and labels
• 🛠 Code is written according to the code quality guidelines
• 🧪 and 🛠 Documentation is available -> does this need documentation?
• 🛠 Unit tests have been added
• 🛠 Changes are backward compatible
• 🛠 The list of authors is up to date
• 🛠 All checks below this pull request were successful

---

To help with the number pull requests:

• 🙏 We kindly ask you to review two other open pull requests in this repository

[codecov]

Codecov Report

Merging #1899 (6c6086e) into main (69a284d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1899   +/-   ##
=======================================
  Coverage   92.03%   92.03%           
=======================================
  Files         234      234           
  Lines       12034    12042    +8     
=======================================
+ Hits        11075    11083    +8     
  Misses        959      959           

Impacted Files	Coverage Δ
esmvalcore/_task.py	71.62% <ø> (ø)
esmvalcore/_provenance.py	97.59% <100.00%> (+0.12%)	⬆️
esmvalcore/_recipe/recipe.py	96.19% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[valeriupredoi]

Looking good, man! 🍺 Test case can be generalized a bit more with filenames that vary a bit more and are resemblant with provenance file names, but heyho - no biggie 😁

[mo-abodas]

Looks good to me. I've tested my recipe with these changes and the plots are nicely ordered now. Thanks!

[schlunma]

Nice one! @total_ordering seems very useful! Thanks @bouweandela 👍