Commit 540b753bf8 introduced
support for resources stored as ir.attachment records in
asset bundles too.
This is specifically useful for customizations.
However the HTTP route for reaching those resources
when they are *not* in a bundle was originally created
in the `website` module (as a special handling for
404 requests)
This means that these dynamic resources would only
be partially supported when `website` is not installed,
causing various problems:
- missing resources in debug mode where bundles are skipped
- errors when trying to define new client-side Qweb templates
via XML resources - which are loaded with a direct request
- ...
This commit moves back the supporting code to the web module.
The `mimetype` column is not present in ir.attachment without
the `website` module, but sniffing it based on the attachment
name works fine at serving time too.
Closes#6002
95b921d0f7