pass showKeys as prop to merchant-details child and use emit to toggle (#105)

previously, index and its child compoment merchant-details had their own
booleans and their values were not synched. Using a prop avoids this
problem

static/js/index.js

@@ -58,8 +58,8 @@ const merchant = async () => {
       showImportKeysDialog: async function () {
         this.importKeyDialog.show = true
       },
-      toggleMerchantKeys: function (value) {
-        this.showKeys = value
+      toggleShowKeys: function () {
+        this.showKeys = !this.showKeys
       },
       toggleMerchantState: async function () {
         const merchant = await this.getMerchant()