58789: Rest call for editing schema (returns 415 unsupported media type atm) + improvements to delete

* added metadata schema form, with the form model fields & validation and layout
* fixed the pagination for schemas and fields
* added reducer and actions for the registry state

Conflicts:
	src/app/core/data/comcol-data.service.ts
	src/server.ts

Angular6 upgrade

Hide the wrapper component when there is no text content

Fixed issue where facets could not be changed when you are logged in

Conflicts:
	src/app/core/cache/builders/remote-data-build.service.ts
	src/app/core/shared/operators.ts

Merge branch 'resolvers-branch-angular6' of https://git.atmire.com/contributions/dspace-angular into patch-support

Conflicts:
	src/app/core/cache/builders/remote-data-build.service.ts
	src/app/core/metadata/metadata.service.ts
	src/app/core/shared/item.model.ts
	src/app/shared/loading/loading.component.ts
	yarn.lock

Conflicts:
	src/app/app.module.ts

Issue 313: add support for paginated properties on dspace objects

Issue 311: No files item page bugfix

#293 Added link with the query quoted for search results if empty