feat: add global prefetch apollo provider option (#710)

Author: Austio

docs/api/apollo-provider.md

@@ -33,6 +33,8 @@ const apolloProvider = new VueApollo({
     console.log('Global error handler')
     console.error(error)
   },
+  // Globally turn off prefetch ssr
+  prefetch: Boolean
 })
 ```
 

src/apollo-provider.js

@@ -8,6 +8,7 @@ export class ApolloProvider {
     this.defaultOptions = options.defaultOptions
     this.watchLoading = options.watchLoading
     this.errorHandler = options.errorHandler
+    this.prefetch = options.prefetch
 
     this.prefetchQueries = []
   }

src/mixin.js

@@ -93,7 +93,7 @@ function launch () {
         const smart = this.$apollo.addSmartQuery(key, options)
         if (this.$isServer) {
           options = reapply(options, this)
-          if (options.prefetch !== false && apollo.$prefetch !== false && !smart.skip) {
+          if (apolloProvider.prefetch !== false && options.prefetch !== false && apollo.$prefetch !== false && !smart.skip) {
             this.$_apolloPromises.push(smart.firstRun)
           }
         }