Add task filter for lists and namespaces (#748)

Add more tests for getting namespaces

Fix namespaces not found

Fix namespaces not found

Make like the default

Update docs & fix docs

Enable searching namespaces by their ids

Enable searching lists by their ids

Enable searching labels by their ids

Enable searching by user ids

Update docs

Add namespace filter

Add task filter for lists

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/748
Co-Authored-By: konrad <konrad@kola-entertainments.de>
Co-Committed-By: konrad <konrad@kola-entertainments.de>

pkg/models/task_collection_test.go

@@ -941,6 +941,46 @@ func TestTaskCollection_ReadAll(t *testing.T) {
 			},
 			wantErr: false,
 		},
+		{
+			name: "filter list",
+			fields: fields{
+				FilterBy:         []string{"list_id"},
+				FilterValue:      []string{"6"},
+				FilterComparator: []string{"equals"},
+			},
+			args: defaultArgs,
+			want: []*Task{
+				task15,
+			},
+			wantErr: false,
+		},
+		{
+			name: "filter namespace",
+			fields: fields{
+				FilterBy:         []string{"namespace"},
+				FilterValue:      []string{"7"},
+				FilterComparator: []string{"equals"},
+			},
+			args: defaultArgs,
+			want: []*Task{
+				task21,
+			},
+			wantErr: false,
+		},
+		{
+			name: "filter namespace in",
+			fields: fields{
+				FilterBy:         []string{"namespace"},
+				FilterValue:      []string{"7,8"},
+				FilterComparator: []string{"in"},
+			},
+			args: defaultArgs,
+			want: []*Task{
+				task21,
+				task22,
+			},
+			wantErr: false,
+		},
 	}
 
 	for _, tt := range tests {