perf(command): user grant pre-condition check using the search table (#8230)

# Which Problems Are Solved

Imporve the performance of user grant addition, especially for import.

# How the Problems Are Solved

Use the search table to query for the project grant state. 
This could easily be done by making the search used in
`checkProjectGrantPreCondition` reusable.

# Additional Changes

Chanded event declerations to `const` in the
`internal/repository/project` package.

# Additional Context

- Performance improvements for import are evaluated and acted upon
internally at the moment

---------

Co-authored-by: adlerhurst <silvan.reusser@gmail.com>
Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/feature/feature.go

@@ -44,6 +44,7 @@ const (
 	ImprovedPerformanceTypeOrgByID
 	ImprovedPerformanceTypeProjectGrant
 	ImprovedPerformanceTypeProject
+	ImprovedPerformanceTypeUserGrant
 )
 
 func (f Features) ShouldUseImprovedPerformance(typ ImprovedPerformanceType) bool {