Unmark config values when planning a data source read

[jbardin]

If the configuration is storing sensitive values in a data source which cannot be read at plan time, those values must be unmarked before creating a planned read value.

This also updates the UpgradeResourceState codepaths to use Diagnostics, and add configuration context when possible.

Fixes #28535

[codecov]

Codecov Report

Merging #28539 (1db29d7) into main (89f986d) will increase coverage by 0.00%.
The diff coverage is 75.00%.

Impacted Files	Coverage Δ
terraform/node_resource_abstract.go	79.61% <54.16%> (-0.12%)	⬇️
terraform/node_resource_abstract_instance.go	73.27% <100.00%> (+0.02%)	⬆️
terraform/node_resource_apply_instance.go	50.47% <100.00%> (ø)
terraform/node_resource_destroy.go	61.36% <100.00%> (ø)
terraform/node_resource_destroy_deposed.go	62.85% <100.00%> (+3.43%)	⬆️
terraform/node_resource_plan_instance.go	73.78% <100.00%> (-0.50%)	⬇️
terraform/node_resource_plan_orphan.go	72.72% <100.00%> (-1.19%)	⬇️
dag/marshal.go	61.90% <0.00%> (-1.59%)	⬇️
terraform/evaluate.go	52.77% <0.00%> (-0.42%)	⬇️

[mildwonkey]

LGTM!

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active contributions.
If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.