erp5_core should contain only the minimal objects needed during
bootstrap phases to install other business templates, but it also
contained all the user interface to edit and maintain the code, run test
and all of this is not strictly required at this point.

ERP5Type: {CSS,JS}Packer have never been used so delete them rather than migrating them to portal_components.

This reverts commit 1862fdf5.
Because of current ERP5Type.Core.Folder inheritance order, this commit
is not ready for inclusion in master just yet.

All ERP5UI-visible (hence needing to call allowedContentTypes) BTReeFolder2
instances should already inherit ERP5Type.Core.Folder, removing the need
for this monkey-patch.

In preparation of reordering Folder inheritance order.

An insolvency proceeding represent a justice decision about the insolvency of a person or an organization.

An insolvency proceeding is defined by: an Insolvency Proceeding Type, a Creditor, a Debtor, Judicial Administrator, Judicial Representative.
The insolvency proceeding follow the ticket workflow

This test should catch when business templates metadata in `bt/` is different from the actual content in `*TemplateItem/` . It should not happen, but sometimes we can forgot to include one or the other in commit.

This also fixes problems in the currently tested business templates, there was three kind of problems:
 * binary files are now exported with `bin` extension, it use to be `obj`.
 * In several business templates, we export categories as `portal_categories/category/*`, while this looks convenient, it's problematic when categories are added by other business templates, every time developer export the business template they have to consider whether the new paths should be exported or not. This changed to list explicitly all the paths to include in business template.
 * some business templates were partially commited ( "erp5_dms_ui_test:  Add selenium tests" )

/reviewed-on !1049

Make it pass coding style

"Hide" an action that is not really useful and problematic when used by mistake

/reviewed-on !1051

This way, the substitution mapping method can return a dynamic mapping,
the only requirement is to implement __getitem__

ne use case is to be able to use the same substitution script for
different CRM notification messages and only compute the "heavy"
substitution variables when they are actually needed.

See nexedi/erp5!1047

We run them in coding style test suite already.

Also these test now need business template repository properly
configured in template tool, which is not set in default setup, so
keeping them working would require extra work.

This reverts commit f9391847.

These two paths were only half-committed, for the PDF we don't have the
file content, for the test we don't have the .xml, so in practice this
test never ran.
I tried to run it but it does not pass, uses pause command and some
xpath selector that are now unclear.

PDFJS is also tested in portal_tests/erp5_km_zuite/testCheckPDFPreview