Project information drop-down values now preserve display labels

cm.abstract.projectInfo now stores and restores project-information drop-down selections in a way that preserves the selected item's label as well as its key.

This fixes a visible behavior issue in paper view and other text-driven outputs where fields such as terms of delivery, delivery method, terms of payment, and delivery time could show only the stored numeric/key value instead of the human-readable label.

class ProjectInformationDialog

ProjectInformationDialog now treats drop-down values as key-and-label pairs instead of only returning a single string value.

Changed behavior/important usage: drop-down field values can now be returned as `<str, str>` key/label pairs
Changed behavior/important usage: drop-down field restoration now looks up the saved label first, then falls back to the saved key

If you extend the dialog or depend on the stored value format for project-information drop-downs, review any code that assumes those controls round-trip only a single string.

Project-information text output now shows labels instead of raw stored keys

When a project-information field is backed by a drop-down, CET now prefers the selected item's label when presenting that value in paper view and similar text output.

That means fields such as:

• terms of delivery
• delivery method
• terms of payment
• delivery time

can now render the expected text instead of only the stored numeric or internal key value.