puavo-web: add puavoDeviceImage to the bootserver form
puavo-rest: fix typo
puavo-rest: preferred_image by bootserver
Revert "rest: read tags from school too"

This reverts commit 98a0346701fbdcb5e798300c2e484663dba41f2a.
Revert "rest: Add tags to school"

This reverts commit d1c489ac7649b6428391d3a498d7f9af9e418c0f.