Sort ref ordering within components

[brynpickering]

update

Fixes #616

Summary of changes in this pull request

• Rebuild references in the order they appear in the backend model dataset, which is the same order they are added to it (so expressions that depend on previous expressions will be built in the correct order).
• Remove investment cost from demands in the dummy test model - this leads to a change in shadow prices which I have updated, but there's no way of knowing if the new shadow prices (or, indeed, the old ones) are correct.
• Force verbose strings on rebuilt backend model components, if verbose strings have already been triggered.

Reviewer checklist

• [ ] Test(s) added to cover contribution
• [ ] Documentation updated
• [ ] Changelog updated
• [ ] Coverage maintained or improved

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 96.08%. Comparing base (872978d) to head (5e80df2). Report is 16 commits behind head on main.

:exclamation: Current head 5e80df2 differs from pull request most recent head 8879a79

Please upload reports for the commit 8879a79 to get more accurate results.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #623 +/- ## ========================================== + Coverage 95.85% 96.08% +0.22% ========================================== Files 24 24 Lines 3619 3649 +30 Branches 788 734 -54 ========================================== + Hits 3469 3506 +37 + Misses 86 81 -5 + Partials 64 62 -2 ``` | [Files](https://app.codecov.io/gh/calliope-project/calliope/pull/623?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=calliope-project) | Coverage Δ | | |---|---|---| | [src/calliope/backend/backend\_model.py](https://app.codecov.io/gh/calliope-project/calliope/pull/623?src=pr&el=tree&filepath=src%2Fcalliope%2Fbackend%2Fbackend_model.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=calliope-project#diff-c3JjL2NhbGxpb3BlL2JhY2tlbmQvYmFja2VuZF9tb2RlbC5weQ==) | `98.07% <100.00%> (+0.16%)` | :arrow_up: | | [src/calliope/backend/pyomo\_backend\_model.py](https://app.codecov.io/gh/calliope-project/calliope/pull/623?src=pr&el=tree&filepath=src%2Fcalliope%2Fbackend%2Fpyomo_backend_model.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=calliope-project#diff-c3JjL2NhbGxpb3BlL2JhY2tlbmQvcHlvbW9fYmFja2VuZF9tb2RlbC5weQ==) | `95.59% <100.00%> (+0.17%)` | :arrow_up: | ... and [13 files with indirect coverage changes](https://app.codecov.io/gh/calliope-project/calliope/pull/623/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=calliope-project)

[brynpickering]

Thanks for the comments @irm-codebase - updated!