fix bug

fix passing of custom file to block

fix custom-file creation on client side

working on crud custom file api for courseware blocks

create correct link for custom file

add read part of CRUD

add delete part of CRUD

change behaviour of add a new file, contents are passed via separate route

update custom-file content

add route to patch metadata of custom-file

changes to export for reference

fix jsonapi for custom-files

export custom-files

correctly import custom files

remove custom files from file-refs

revert changes to block

remove obsolte use statement in Block

revert changes to BlockType and Download-Block

remove obsolete implements from DownloadBlock

add doku, fix exporting of blocks without custom-files

remove debugging messages and now obsolete code

cleaning up

rework custom file check

fix error and remove call to mime-type for custom files

rename interface methods

do not assign variables in function calls