Add hashtag following button (#244)

Co-authored-by: FloatingGhost <hannah@coffee-and-dreams.uk>
Reviewed-on: https://akkoma.dev/AkkomaGang/pleroma-fe/pulls/244

src/modules/tags.js

@@ -0,0 +1,37 @@
+import { merge } from 'lodash'
+
+const tags = {
+  state: {
+    // Contains key = id, value = number of trackers for this poll
+    tags: {}
+  },
+  mutations: {
+    setTag (state, { name, data }) {
+      state.tags[name] = data
+    }
+  },
+  actions: {
+    getTag ({ rootState, commit }, tagName) {
+      return rootState.api.backendInteractor.getHashtag({ tag: tagName }).then(tag => {
+        commit('setTag', { name: tagName, data: tag })
+        return tag
+      })
+    },
+    followTag (store, tagName) {
+      return store.rootState.api.backendInteractor.followHashtag({ tag: tagName })
+        .then((resp) => {
+          store.commit('setTag', { name: tagName, data: resp })
+          return resp
+        })
+    },
+    unfollowTag ({ rootState, commit }, tag) {
+      return rootState.api.backendInteractor.unfollowHashtag({ tag })
+        .then((resp) => {
+          commit('setTag', { name: tag, data: resp })
+          return resp
+        })
+    }
+  }
+}
+
+export default tags