[patch] fix qr base64 encoding function (#1079)

# Pull Request Template

## Description

In
https://github.com/BranchMetrics/web-branch-deep-linking-attribution/pull/1075/files,
i tried to clean up the function a little bit. However, i broke it. So,
i returned the function to normal, but instead jammed the new encoding
of the bytes in. So all should be good

Fixes # (issue)

## Type of change

Please delete options that are not relevant.

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

## How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details
for your test configuration

- [ ] Unit test
- [ ] Integration test

## JS Budget Check

Please mention the size in kb before abd after this PR

| Files            | Before      | After       | 
| -----------      | ----------- | ----------- |
| dist/build.js.   |             |             |
| dist/build.min.js|             |             |

## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules
- [ ] I have checked my code and corrected any misspellings

## Mentions: 
List the person or team responsible for reviewing proposed changes.

cc @BranchMetrics/saas-sdk-devs for visibility.

Author: bredmond5

dist/build.js

@@ -3106,13 +3106,18 @@ Branch.prototype.link = wrap(callback_params.CALLBACK_ERR_DATA, function(a, b) {
 });
 Branch.prototype.qrCode = wrap(callback_params.CALLBACK_ERR_DATA, function(a, b, c, d) {
   utils.cleanLinkData(b).qr_code_settings = safejson.stringify(utils.convertObjectValuesToString(c || {}));
-  this._api(resources.qrCode, utils.cleanLinkData(b), (e, f) => e ? a(e, null) : a(null, {rawBuffer:f, base64() {
-    if (!this.rawBuffer) {
-      throw Error("QrCode.rawBuffer is empty.");
+  this._api(resources.qrCode, utils.cleanLinkData(b), function(e, f) {
+    function g() {
     }
-    const g = Array.from(new Uint8Array(this.rawBuffer)).map(h => String.fromCharCode(h)).join("");
-    return btoa(g);
-  }}));
+    e || (g.rawBuffer = f, g.base64 = function() {
+      if (this.rawBuffer) {
+        const h = Array.from(new Uint8Array(this.rawBuffer)).map(k => String.fromCharCode(k)).join("");
+        return btoa(h);
+      }
+      throw Error("QrCode.rawBuffer is empty.");
+    });
+    return a(e || null, g || null);
+  });
 });
 Branch.prototype.deepview = wrap(callback_params.CALLBACK_ERR, function(a, b, c) {
   var d = this;