Need "skipped" database entries

[smoelius]

E.g., in the following places:

necessist/core/src/outcome.rs

Lines 13 to 16 in c441b83

	Nonbuildable,
	Failed,
	TimedOut,
	Passed,

necessist/core/src/create_table_removal.sql

Line 4 in c441b83

outcome TEXT NOT NULL CHECK (outcome IN ('nonbuildable', 'failed', 'timed-out', 'passed')),

Something that I think is happening now is:

• A dry-run fails.
• The associated tests are skipped.
• When later asked to resume, Necessist complains because of missing database entries.

[smoelius]

Fixed by #936