[FIX] payment_paypal: paypal IPN, receiver_id is not always passed

The method  _paypal_form_get_invalid_parameters checks that the params passed by the paypal feedback coroborate with the transaction requested by Odoo.

It looks like the 'receiver_id' is not always passed by the paypal feedback. Therefore, we check this param only if it is available in the paypal feeback.

This issue had as side-effect to not validate the paypal transaction, which remained 'draft' permanently.
[FIX] payment*: add the customer state to payment (paypal) transactions
[FIX] res_partner: commercial partner sync

On child partner creation of a parent partner, the commercial_partner_id is not computed (and stored) in the create method.
Therefore, we should compute the commercial_partner_id before trying to sync his data
[FIX] survey: missing timezone conversions

As the survey hardcode lot's of views and reports in python, we do not beneficiate from automatic timezone conversions in the webclient.
Hopefully this is fixed in v8 after refactoring of the survey module. opw 608786
[ADD] res_partner: test case for fix rev 4a278809741d4e961ac13d3477a046d43b32cfa7
[MERGE] forward port of branch 7.0 up to e07bc5d
[MERGE] forward port of branch saas-3 up to ebf317a