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/domain/project_grant.go

@@ -18,8 +18,14 @@ const (
 	ProjectGrantStateActive
 	ProjectGrantStateInactive
 	ProjectGrantStateRemoved
+
+	projectGrantStateMax
 )
 
+func (s ProjectGrantState) Valid() bool {
+	return s > ProjectGrantStateUnspecified && s < projectGrantStateMax
+}
+
 func (p *ProjectGrant) IsValid() bool {
 	return p.GrantedOrgID != ""
 }