improve fog-aws / s3 upload

[tmfrnz]

• get asset folder from environment
• use client URL instead of client URL (this will only work if the asset folder is set up inside the same bucket as the client app)

[tmfrnz]

hi @parndt, could you review this and clean it up where required?

the idea is that the signed url AWS returns is hidden from the client and we use the client URL instead (which is hosted in the same bucket)

now there is probably be a better way to do the URL replacement. also we should consider making it optional (from another ENV variable?) and also fix those failing checks

[parndt]

@tmfrnz how's this looking?

[tmfrnz]

@tmfrnz how's this looking?

happy to confirm that this appears to be working well on UAT