CBMS ERP Base import

New extensible file import for CBMS ODOO
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Re-implement CBMS ODOO’s file import system:

* Server side, the previous system forces most of the logic into the
client which duplicates the effort (between clients), makes the
import system much harder to use without a client (direct RPC or
other forms of automation) and makes knowledge about the
import/export system much harder to gather as it is spread over
3+ different projects.

* In a more extensible manner, so users and partners can build their
own front-end to import from other file formats (e.g. OpenDocument
files) which may be simpler to handle in their work flow or from
their data production sources.

* In a module, so that administrators and users of CBMS ODOO who do not
need or want an online import can avoid it being available to users.