chore(lib): update Checkbox

- In `src/components/checkbox/Checkbox.vue`,
    - `disabled` attributes are bound to `disableOrUndefined` that
      is newly introduced to `CheckRadioMixin` (see below).
- In `src/utils/CheckRadioMixin.js`,
    - The default `v-model` binding is updated.
        - `value` --> `modelValue`
        - `input` --> `update:modelValue`
    - `disabledOrUndefined` that takes `true` or `undefined`. This is
      introduced to support new behavior of Vue 3. On Vue 3, setting
      a boolean attribute `false` does not remove it. To do so,
      `null` or `undefined` has to be given instead.
- Automatic ESLint fix is applied.

src/components/checkbox/Checkbox.vue

@@ -3,10 +3,11 @@
         class="b-checkbox checkbox"
         :class="[size, { 'is-disabled': disabled }]"
         ref="label"
-        :disabled="disabled"
+        :disabled="disabledOrUndefined"
         @click="focus"
         @keydown.prevent.enter="$refs.label.click()"
-        @keydown.prevent.space="$refs.label.click()">
+        @keydown.prevent.space="$refs.label.click()"
+    >
         <!-- Checkbox needs to listen for a space event instead of a just a
              click and enter event so that that using the keyboard spacebar will also
              trigger the checkbox change in the b-table -->
@@ -18,15 +19,16 @@
             ref="input"
             @click.stop
             :autocomplete="autocomplete"
-            :disabled="disabled"
+            :disabled="disabledOrUndefined"
             :required="required"
             :name="name"
             :value="nativeValue"
             :true-value="trueValue"
             :false-value="falseValue"
-            :aria-labelledby="ariaLabelledby">
+            :aria-labelledby="ariaLabelledby"
+        >
         <span class="check" :class="type" />
-        <span :id="ariaLabelledby" class="control-label"><slot/></span>
+        <span :id="ariaLabelledby" class="control-label"><slot /></span>
     </label>
 </template>
 

src/utils/CheckRadioMixin.js

@@ -1,6 +1,6 @@
 export default {
     props: {
-        value: [String, Number, Boolean, Function, Object, Array],
+        modelValue: [String, Number, Boolean, Function, Object, Array],
         nativeValue: [String, Number, Boolean, Function, Object, Array],
         type: String,
         disabled: Boolean,
@@ -10,7 +10,7 @@ export default {
     },
     data() {
         return {
-            newValue: this.value
+            newValue: this.modelValue
         }
     },
     computed: {
@@ -20,15 +20,21 @@ export default {
             },
             set(value) {
                 this.newValue = value
-                this.$emit('input', value)
+                this.$emit('update:modelValue', value)
             }
+        },
+        disabledOrUndefined() {
+            // On Vue 3, setting a boolean attribute `false` does not remove it.
+            // To remove it, `null` or `undefined` has to be given.
+            // Setting `false` ends up with a grayed out component.
+            return this.disabled || undefined
         }
     },
     watch: {
         /**
         * When v-model change, set internal value.
         */
-        value(value) {
+        modelValue(value) {
             this.newValue = value
         }
     },