Status output for importswid command
Removed encoding argument from prettify_xml

Input to the function should always be unicode. The assumed output
encoding is alwalys UTF-8.
Add tag-file relations in chunks

SQLite does not allow more than 999 parameters to be present. When
adding more than 999 files to a tag using `tag.files = [...]`, it will
fail with an OperationalError.

This commit adds chunking to the `process_swid_tag` function. The
TagFile instances are created in bulk using chunks of 950 items.
Created new apps
Separated tpm app
Moved fields to apps.core.fields
Separated filesystem app
Separated devices app
Separated packages app
Separated policies app
Separated core and front apps, removed tncapp

This commit fully removes the old `tncapp` app. Instead, everything is
split up into multiple Django apps in the `apps` directory.
Fixed failing tests
SWID test data