initial-data fixture for empty dbs (improved)

This reverts commit 6b7d84646676b896c4e75bc5b962ebc31588417a.
Merge pull request #2467 from chuckharmston/1058163

Remove background_color from FeedShelf model (bug 1058163)
Request Tarako review on app status page (bug 1040347)
Merge pull request #2462 from mstriemer/request-tarako-review-1040347

Request Tarako review on app status page (bug 1040347)
India as a low-memory region (bug 1057089)
Merge pull request #2463 from mstriemer/india-region-1057089

India as a low-memory region (bug 1057089)
Merge pull request #2470 from washort/init-fixture

initial-data fixture for empty dbs (improved)
Remove accidental asset bundle file
Fix migration conflict
move from_search to WebappIndexer