Remove housing pages now managed by Drupal.

[kevwalsh]

Page to edit

https://www.va.gov/housing-assistance

Origin of request (internal/stakeholder/user feedback)

https://prod.cms.va.gov/section/veterans-benefits-administration/housing-assistance-benefits-hub shows that all this content is now published in Drupal, so we can delete it.

[kevwalsh]

@RLHecht This PR deletes 22 files from vagov-content, but there are only 15 listed at https://prod.cms.va.gov/section/veterans-benefits-administration/housing-assistance-benefits-hub (plus the one Housing Assistance landing pages which is in a different section). Does that make sense to you that 6 files were either moved or consolidated from housing?

[RLHecht]

@kevwalsh Some of the pages that are in vagov-content look like new URLs for legacy pages, though they aren't live with any info. I can see that one page was moved from the hub.

[kevwalsh]

@RLHecht Yeah Looks like they are just menu items, which don't show up on that list of 15.

[va-bot]

⚠️ This content failed to build with the following output:

Error: request to https://prod.cms.va.gov/flags_list failed, reason: connect ECONNREFUSED 127.0.0.1:2001
    at ClientRequest.<anonymous> (/application/node_modules/node-fetch/lib/index.js:1369:11)
    at ClientRequest.emit (events.js:198:13)
    at onerror (/application/node_modules/socks-proxy-agent/node_modules/agent-base/index.js:101:9)
    at callbackError (/application/node_modules/socks-proxy-agent/node_modules/agent-base/index.js:123:5)
    at process._tickCallback (internal/process/next_tick.js:68:7)