[FIX] web: regard the view_list has valid if not yet loaded

This fix is related to df845940ed52040ef92b1b5759306c556fa38e66

Fixes #3469
[MERGE] forward port of branch 7.0 up to 9a37e5a
[MERGE] forward port of branch saas-3 up to c11451c
[FIX] ir_qweb, website_blog: Allow to pass inline style as an option for the widget image. And change some img from blog to use this widget
[IMP] models: improve _mapped_func(), and add parameter 'reverse' in sorted()
[FIX] Report: get_pdf:  don't miss main elements when parsing html

Main elements can have more than one class, thus can be ignored by the previous
naive xpath. This patch brings a stronger xpath.
[FIX] product: pricelists based on the supplier prices now return first supplier price if partner not in suppliers instead of returning 0

Without this, sale pricelists cannot be based on supplier prices as the partner is never a supplier so the price would be 0
Note: behavior change ok with fp
[FIX] mrp: chain product move and MO locations

When validating a SO containing a `make to stock` + `manufacture` product
(with bom + orderpoint), we have the following stock moves:
* Product move
* Manufacturing order
Selling 1 such product would yield 2 as incoming quantity, an
inconsistency that this commit solves by setting the location_id of the
product move to the MO's location_dest_id (in the same fashion that
the create_pickings method does in an mts/buy case)

opw-616229
[FIX] ir_qweb: contact widget: use name_get instead of display_name

display_name field is overidden in res.partner in order to pop the context
key leading to show the address, and we want the address.
[FIX] web: inhibit on change flag when validating editable list

To valid all editable list line, we iterate on the lines and set the editor form with the line value, using set_value.
The _inhibit_on_change_flag should be set to True to avoid triggering on changes events

opw-617395
[MERGE] forward port of branch 7.0 up to cd69dee
[MERGE] forward port of branch saas-3 up to c666030
Revert "[FIX] mrp: chain product move and MO locations"

This reverts commit 61a8971db510dbb0e087bba09858fe8b94c7b16d.

This rev. is from a 7.0 forward port b4d602fdd3379a0310ec0b9a56f9b88226

This is no longer needed in 8.0, with the new WMS
[ADD] doc: tentative guide to the new API

Turns out most people have a hard time understanding the new API from no
documentation (or just the API documentation) or just the opendays slides
things (not to mention things have changed since).

Tries to lay down some basics and porting info.