UID is not a list

The `_verbose` attribute of `SlapOSInstanceTestCase` was unused and it
is now removed.
As the `makeModuleSetUpAndTestCaseClass` needed to be edited to remove
`_verbose` from the class type instantiation, that function has been
formatted, documented and typed.

See merge request nexedi/slapos.core!664

Class attributes of `SlapOSInstanceTestCase` have been typed and
documented.

See merge request nexedi/slapos.core!664

This adds the `request_instance` class variable to
`SlapOSInstanceTestCase`.
If this variable is false, no instance will be requested.

See merge request nexedi/slapos.core!664

 - warn with all json validation errors, not just the first one
 - make validation error message easier to understand by not including
   so many useless details
 - do not let jsonschema fetch schema references by providing our own
   fetch implementation

Do not access destination section value when updating instance tree,
as manager can't access customer info

slapos_accounting: a single payment transaction can be used to pay multiple invoices with different destinations

Define the source_project on the newly created Sale Trade Condition

slapos_subscription_request: cancel existing subscription request if a new trade condition is detected

Do not crash if subscription could not be created anymore

slapos_upgrader: do not fixup instance tree virtual master if one software instance is in the same virtual master

Ensure people can see projects they used to see before migration

  Whenever the allocated shared (slave) instance is destroyed or stopped, isn't included on the getComputerInformation, so the timestamp can eventually go back in time (so partition skips process).

  This ensures that the partition information gets a newer timestamp (larger them the previous one).

   All timestamps parameters should be int, and be consistent accross
   the parameters.

   The client compare previous/fetched as float, so use string can break
   later on if we introduce a non-numeric value on returned dict.

    Check if bang_timestamp is consistent and updated
    accordingly by the normal usage.

    Whenever an instance is allocated the partition must
    update its bang_timestamp.

    Ensure the implementation is consistent with the precision (1e6) otherwise partition modification date will never
    ever be larger, when compared.

  This ensure that timestamp is updated, and enforces that cache is updated

Instances were not allocated on this project in reality.

It is otherwise difficult for a Project Manager to access it on the panel

Only payable deliveries will generate invoices.