Refactor adding tags to an event

Also refactor extracting tags from content, now uses Pleroma's Formatter

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/components/Event/TagInput.vue

@@ -0,0 +1,54 @@
+<template>
+    <b-field label="Enter some tags">
+        <b-taginput
+                v-model="tags"
+                :data="filteredTags"
+                autocomplete
+                :allow-new="true"
+                :field="path"
+                icon="label"
+                placeholder="Add a tag"
+                @typing="getFilteredTags">
+        </b-taginput>
+    </b-field>
+</template>
+<script lang="ts">
+import { Component, Prop, Vue, Watch } from 'vue-property-decorator';
+import { get } from 'lodash';
+import { ITag } from '@/types/tag.model';
+@Component
+export default class TagInput extends Vue {
+
+  @Prop({ required: false, default: () => [] }) data!: object[];
+  @Prop({ required: true, default: 'value' }) path!: string;
+  @Prop({ required: true }) value!: string;
+
+  filteredTags: object[] = [];
+  tags: object[] = [];
+
+  getFilteredTags(text) {
+    this.filteredTags = this.data.filter((option) => {
+      return get(option, this.path)
+                .toString()
+                .toLowerCase()
+                .indexOf(text.toLowerCase()) >= 0;
+    });
+  }
+
+  @Watch('tags')
+  onTagsChanged (tags) {
+    const tagEntities = tags.map((tag) => {
+      if (TagInput.isTag(tag)) {
+        return tag;
+      }
+      return { title: tag, slug: tag } as ITag;
+    });
+    console.log('tags changed', tagEntities);
+    this.$emit('input', tagEntities);
+  }
+
+  static isTag(x: any): x is ITag {
+    return x.slug !== undefined;
+  }
+}
+</script>