feat: Notifiers CRUD (#337)

* introduce scaffold for new models

* wip: shoutrrr wrapper (may remove)

* update schema files

* gen: ent code

* gen: migrations

* go mod tidy

* add group_id to notifier

* db migration

* new mapper helpers

* notifier repo

* introduce experimental adapter pattern for hdlrs

* refactor adapters to fit more common use cases

* new routes for notifiers

* update errors to fix validation panic

* go tidy

* reverse checkbox label display

* wip: notifiers UI

* use badges instead of text

* improve documentation

* add scaffold schema reference

* remove notifier service

* refactor schema folder

* support group edges via scaffold

* delete test file

* include link to API docs

* audit and update documentation + improve format

* refactor schema edges

* refactor

* add custom validator

* set validate + order fields by name

* fix failing tests

backend/internal/web/adapters/decoders.go

@@ -0,0 +1,52 @@
+package adapters
+
+import (
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/google/uuid"
+	"github.com/gorilla/schema"
+	"github.com/hay-kot/homebox/backend/internal/sys/validate"
+	"github.com/hay-kot/homebox/backend/pkgs/server"
+)
+
+var queryDecoder = schema.NewDecoder()
+
+func decodeQuery[T any](r *http.Request) (T, error) {
+	var v T
+	err := queryDecoder.Decode(&v, r.URL.Query())
+	if err != nil {
+		return v, err
+	}
+
+	err = validate.Check(v)
+	if err != nil {
+		return v, err
+	}
+
+	return v, nil
+}
+
+func decode[T any](r *http.Request) (T, error) {
+	var v T
+
+	err := server.Decode(r, &v)
+	if err != nil {
+		return v, err
+	}
+
+	err = validate.Check(v)
+	if err != nil {
+		return v, err
+	}
+
+	return v, nil
+}
+
+func routeUUID(r *http.Request, key string) (uuid.UUID, error) {
+	ID, err := uuid.Parse(chi.URLParam(r, key))
+	if err != nil {
+		return uuid.Nil, validate.NewRouteKeyError(key)
+	}
+	return ID, nil
+}