Fix/contentful add header (#29028)

* contentful: enrich API requests with integration name and version

* build: upgrade to latest Contentful SDK

Author: axe312ger

packages/gatsby-source-contentful/package.json

@@ -15,7 +15,7 @@
     "base64-img": "^1.0.4",
     "bluebird": "^3.7.2",
     "chalk": "^4.1.0",
-    "contentful": "^7.14.12",
+    "contentful": "^8.1.7",
     "fs-extra": "^9.0.1",
     "gatsby-core-utils": "^1.9.0-next.0",
     "gatsby-plugin-utils": "^0.8.0-next.1",

packages/gatsby-source-contentful/src/fetch.js

@@ -19,6 +19,7 @@ module.exports = async function contentfulFetch({
     host: pluginConfig.get(`host`),
     environment: pluginConfig.get(`environment`),
     proxy: pluginConfig.get(`proxy`),
+    integration: `gatsby-source-contentful`,
     responseLogger: response => {
       function createMetadataLog(response) {
         if (process.env.gatsby_log_level === `verbose`) {