Add metatag submodules, cgov_metatag, config exclusions, field storage

[adriancofie]

Adds and enables the following modules:

• cgov_metatag

Enables the following sub modules:

• metatag_dc
• metatag_dc_advanced
• metatag_open_graph
• metatag_twitter_cards

Adds the following config checker exclusions:
'metatag.metatag_defaults.global',
'metatag.metatag_defaults.node',

Closes #185 by adding the following

• Browser Title element
• Meta Description
• Search Engine Restrictions Logic. (Adds no index tag based on the node field value)
  NOTE: The S.E logic will only work for content types that have added a field of type metatag. This PR adds it for article only. When added for the remaining types, this logic will automatically work for them also.

Closes #197 OpenGraph Tabs by adding the following:

• og:title
• og:description
• og:type
• og:url
• og:sitename
• twitter:card

Closes #195 HREF TAG

• (This HREF Lang functionality has actually been in develop for a while and just needs to be verified.)

Partially addressing #196

• Add dcterms.type for Article
  Note: Each content type will need to add a field of type 'metatag' and it's related configuration in the module for the tag to appear .

[adriancofie]

http://ncigovcdode70.prod.acquia-sites.com/

[VictoriaSunNIH]

@adriancofie - we need to discuss what other stories need to be put in for this one. I also tested exclude from search on an article and did not see the "noindex" value in the view source.

[adriancofie]

Updating with latest from develop.

[adriancofie]

Per convo with @VictoriaSunNIH I'm going to attempt to add the metatag field to each content type within this PR.

[VictoriaSunNIH]

@adriancofie - I've tested all of the metadata out on all of the content types.

For node/page types:

• CTHP, Mini Landing Page and Cancer Research List pages are missing their dcterms.type in the metadata

For Media Types:

• Infographic and Videos are missing dcterms.type
• Exclude from Search is not appearing in the view source for both
  • Video: http://ncigovcdode70.prod.acquia-sites.com/about-cancer/coping/feelings/relaxation/hedge-maze
  • Infographic: http://ncigovcdode70.prod.acquia-sites.com/about-nci/organization/nci-at-a-glance

[VictoriaSunNIH]

This looks good! Passes IA review!