[MCKIN-7023] Ensures that default template tags are loaded for Django 1.11

Description

Fixes bug related to the Django 1.11 upgrade and support for translations in XBlock templates added by https://github.com/edx/xblock-utils/pull/48.

Ensures that the standard Django templatetag libraries continue to work in XBlock templates (e.g., [DnDv2](https://github.com/edx-solutions/xblock-drag-and-drop-v2/blob/master/drag_and_drop_v2/templates/html/drag_and_drop_edit.html#L2) uses `l10n`).

*JIRA tickets*: [MCKIN-7023](https://edx-wiki.atlassian.net/browse/MCKIN-7023), OSPR

*Discussions*: (https://openedx.atlassian.net/browse/WL-230), (https://openedx.atlassian.net/browse/YONK-879?focusedCommentId=307771&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-307771)

*Screenshots*:

*Before*
Before this fix and since edx-platform was upgraded to Django 1.11, attempts to edit the DnDv2 XBlock in Studio resulted in this error:
![before](https://user-images.githubusercontent.com/7556571/39793249-c885b98c-5383-11e8-937b-7b09f931c39b.png)

*After* this change, DnDv2 XBlock can be edited as expected:
![after](https://user-images.githubusercontent.com/7556571/39793343-425c5996-5384-11e8-9246-f844b7aabc40.png)

*Sandbox URL*: (provisioning)

*Merge deadline*: ASAP

*Testing instructions*:

1. In Studio, create a course and add a Drag and Drop problem (e.g. [sandbox Drag and Drop](https://studio-pr17670.sandbox.opencraft.hosting/container/block-v1:OpenCraft+DnDv2+2018_1+type@vertical+block@a2b13b1603724df192e1c43dd3f1d70d?action=new#))
1. Edit the DnDv2 XBlock.
Note that this works as expected.

*Reviewers*

  • [ ] @mtyaka

  • [ ] edx-solutions reviewer[s] TBD

CC @macdiesel

Done

Assignee

Unassigned

Reporter

Open Source Pull Request Bot

Labels

None

Contributor Name

Jillian Vogel

Repo

edx/xblock-utils

Customer

Epic Link

None

OSCM Assignee

None

Platform Map Area (Levels 1 & 2)

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Platform Map Area (Levels 3 & 4)

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Blended Hour Utilization Percentage

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edX Theme

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edX Squad

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Github Lines Added

23

Github Lines Deleted

2

Priority

Unset