138 optimize frontend code regarding react hooks

[broekhuisg]

A few fixes and tweaks after the site went to the server:

Images on server not loading 
Unneed usage of react hooks fixed
Grid layout not everywhere available fixed
Pagewrap on staticpage 
TextMedia remove title/size:
TextMedia and Section block frontend moved to blocks folder, same structure as the backend has
Backgroundcolor en size of the background options added to the blocks, front- and backend

[antw]

Looks fine to me. 👍

Thanks for improving <img /> → Image

[pascalalferink]

While I was reviewing this request, this branch was merged.
I had two remarks, I put them in two issues:
#152
#153