feat(group): group service to create, update, and delete groups (#10455)

# Which Problems Are Solved

This PR adds API definition and backend implementation for GroupService
to manage user groups.

# How the Problems Are Solved
* API definition to create, update, retrieve, and delete groups is added
* Command-side implementation to create, update, and delete user groups
as part of the GroupV2 API is added

# Additional Changes
N/A

# Additional Context
- Related to #10089, #9702 (parent ticket)
- User contribution: https://github.com/zitadel/zitadel/pull/9428/files
- Additional functionalities to list/search user groups, add
permissions, manage users in groups, group scopes will be added in
subsequent PRs.
- Also needs documentation, which will be added once the entire feature
is available

---------

Co-authored-by: Livio Spring <[email protected]>

internal/query/group.go

@@ -0,0 +1,27 @@
+package query
+
+import (
+	"context"
+	"time"
+
+	"github.com/zitadel/zitadel/internal/zerrors"
+)
+
+type Groups struct {
+	SearchResponse
+	Groups []*Group
+}
+
+type Group struct {
+	ID            string
+	Name          string
+	Description   string
+	CreationDate  time.Time
+	ChangeDate    time.Time
+	ResourceOwner string
+}
+
+// SearchGroups returns the list of groups that match the search criteria
+func (q *Queries) SearchGroups(ctx context.Context) (*Groups, error) {
+	return nil, zerrors.ThrowUnimplemented(nil, "QUERY-grpfli", "Not implemented")
+}