feat(StatusValidator): allow validators to provide default `errorMessage`

Validators can now define a default `errorMessage` like so:

```qml
StatusValidator {
  ...
  errorMessage: "..."
}
```

Because there's no access to runtime validation errors, `errorMessage` have to
be static. However, if applications wish to provide their own `errorMessage`
they can still override it and make it dynamic:

```qml
SomeValidator {
  ...
  errorMessage: input.errors.someValidator ? "Whoopsie" : ""
}
```

ui/StatusQ/sandbox/StatusInputPage.qml

@@ -84,19 +84,22 @@ Column {
     }
 
     StatusInput {
+        id: input
         label: "Label"
         charLimit: 30
         input.placeholderText: "Input with validator"
 
         validators: [
-            StatusMinLengthValidator { minLength: 10 }
-        ]
-
-        onTextChanged: {
-            if (errors && errors.minLength) {
-                errorMessage = `Value can't be shorter than ${errors.minLength.min} but got ${errors.minLength.actual}`
+            StatusMinLengthValidator {
+                minLength: 10
+                errorMessage: {
+                    if (input.errors && input.errors.minLength) {
+                        return `Value can't be shorter than ${input.errors.minLength.min} but got ${input.errors.minLength.actual}`
+                    }
+                    return ""
+                }
             }
-        }
+        ]
     }
 
     StatusInput {

ui/StatusQ/src/StatusQ/Controls/StatusInput.qml

@@ -34,18 +34,30 @@ Item {
     property var errors: ({})
 
     function validate() {
+        statusBaseInput.valid = true
         if (validators.length) {
             for (let idx in validators) {
-                let result = validators[idx].validate(statusBaseInput.text)
+                let validator = validators[idx]
+                let result = validator.validate(statusBaseInput.text)
 
                 if (typeof result === "boolean" && result) {
-                    statusBaseInput.valid = true
+                    statusBaseInput.valid = statusBaseInput.valid && true
+                    delete errors[validator.name]
                 } else {
                     if (!errors) {
                         errors = {}
                     }
-                    errors[validators[idx].name] = result
-                    statusBaseInput.valid = false
+                    result.errorMessage = validator.errorMessage
+                    errors[validator.name] = result
+                    statusBaseInput.valid = statusBaseInput.valid && false
+                }
+            }
+            if (errors){
+                let errs = Object.values(errors)
+                if (errs && errs[0]) {
+                    errorMessage.text = errs[0].errorMessage || root.errorMessage;
+                } else {
+                    errorMessage.text = ""
                 }
             }
         }
@@ -123,11 +135,11 @@ Item {
         anchors.leftMargin: 16
 
         height: visible ? implicitHeight : 0
-        visible: !!root.errorMessage && !statusBaseInput.valid
+        visible: !!text && !statusBaseInput.valid
 
         font.pixelSize: 12
         color: Theme.palette.dangerColor1
-        text: root.errorMessage
+
 
         horizontalAlignment: Text.AlignRight
         wrapMode: Text.WordWrap

ui/StatusQ/src/StatusQ/Controls/Validators/StatusMinLengthValidator.qml

@@ -6,6 +6,12 @@ StatusValidator {
 
     name: "minLength"
 
+    errorMessage: {
+        minLength === 1 ?
+            "Please enter a value" :
+            `The value must be at least ${minLength} characters.`
+    }
+
     validate: function (value) {
         return value.length >= minLength ? true : {
             min: minLength,

ui/StatusQ/src/StatusQ/Controls/Validators/StatusValidator.qml

@@ -4,6 +4,7 @@ QtObject {
     id: statusValidator
 
     property string name: ""
+    property string errorMessage: "invalid input"
 
     property var validate: function (value) {
         return true