add Block + Component, add TextComponent with min, max and regex validators and early NumberComponent

internal/block/component.go

@@ -0,0 +1,27 @@
+package block
+
+import (
+	"blocky/internal/block/validation"
+	"encoding/json"
+)
+
+type ComponentType int8
+
+const (
+	_ ComponentType = iota
+	TextComponentType
+	NumberComponentType
+	Date
+)
+
+type Component interface {
+	Type() ComponentType
+	Identifier() string
+	Name() string
+	NewInstance() ComponentInstance
+	Validators() []validation.Validator
+}
+
+type ComponentInstance interface {
+	FromJSON(component Component, data json.RawMessage) error
+}