Allow branchName in reg-notify-github-plugin config

[jacobrask]

What does this change?

Allows setting a branch name in the config, enabling something like

  "reg-notify-github-plugin": {
    "branchName": "$GIT_BRANCH_NAME"
  }

This enables a GitHub workflow where there is no deep clone or re-fetch, and the commit shas are all received from Github context, e.g.

      - name: Compare screenshots
        if: github.event_name == 'pull_request'
        env:
          REG_SUIT_EXPECTED_KEY: ${{ github.event.pull_request.base.sha }}
          REG_SUIT_ACTUAL_KEY: ${{ github.event.pull_request.head.sha }}
       run: ... compare

      - name: Publish results
        if: github.event_name == 'pull_request'
        env:
          REG_SUIT_EXPECTED_KEY: ${{ github.event.pull_request.base.sha }}
          REG_SUIT_ACTUAL_KEY: ${{ github.event.pull_request.head.sha }}
          REG_SUIT_BRANCH_NAME: ${{ github.event.pull_request.head.ref }}
       run: ... publish

[jacobrask]

I have implemented and tested this in our own repo with the following patch:

--- a/node_modules/reg-notify-github-plugin/lib/github-notifier-plugin.js
+++ b/node_modules/reg-notify-github-plugin/lib/github-notifier-plugin.js
@@ -39,6 +39,9 @@ class GitHubNotifierPlugin {
         else {
             this._apiOpt = config.options;
         }
+        if (config.options.branchName) {
+            this._apiOpt.branchName = config.options.branchName;
+        }
         this._prComment = config.options.prComment !== false;
         this._setCommitStatus = config.options.setCommitStatus !== false;
         this._apiPrefix = config.options.customEndpoint || reg_gh_app_interface_1.getGhAppInfo().endpoint;
@@ -85,10 +88,12 @@ class GitHubNotifierPlugin {
             reqs.push(statusReq);
         }
         if (this._prComment) {
-            if (head.type === "branch" && head.branch) {
-                const prCommentBody = Object.assign({}, this._apiOpt, { branchName: head.branch.name, failedItemsCount, newItemsCount, deletedItemsCount, passedItemsCount });
+            if ((head.type === "branch" && head.branch) || this._apiOpt.branchName) {
+                const prCommentBody = Object.assign({}, this._apiOpt, { failedItemsCount, newItemsCount, deletedItemsCount, passedItemsCount });
                 if (params.reportUrl)
                     prCommentBody.reportUrl = params.reportUrl;
+                if (!prCommentBody.branchName && head.branch)
+                    prCommentBody.branchName = head.branch.name;
                 const commentReq = {
                     uri: `${this._apiPrefix}/api/comment-to-pr`,
                     method: "POST",

but it's a bit difficult to test this PR