[Fix][8.0] Fix the way pricelists are selected when a template_id is set as rule of pricelist

[llacroix]

Added a method that help matching which pricelist can be used.

It can be inherited which allow other modules to extend the way the
pricelists are chosen.

Also a rule in the while loop could be removed as it duplicated
one of the tests when chosing the available pricelists.

Fix the issue here:
#90

[coveralls]

Coverage decreased (-0.2%) to 41.309% when pulling 94ca89e on llacroix:8_fix_pos_pricelist_template into b66ec78 on OCA:8.0.

[StefanRijnhart]

Where is categ_ids defined?

[llacroix]

Ah this seems to be missing when I moved some code to that method. I'll fix that.

[StefanRijnhart]

Thanks for the fix! I added some small discussion points to the code.

[llacroix]

I fear it might not be that simple. I remember it was working with pos_pricelist alone, but apparently with pos_template there are still some problems :(

[llacroix]

Ah non forget my previous comment, I just forgot to move some code in the function I added. The problem I had is something completely different.

[llacroix]

Any news about this patch?

[rafaelbn]

Hi @ismaelcj @jcarlosmontoya @AdilHoumadi , have you experimented this issue with pos_pricelist? Maybe you could take a look here. Thanks!

[rafaelbn]

Hi @krupesh-weboffice, this PR resolves your issue #90, could you test it please? Thanks!

[rafaelbn]

Hi @llacroix , there have been some changes in travis. Please could you rebase this PR in order to check it again? Thanks

[llacroix]

I guess I can do that. A bit later today.

[legalsylvain]

@llacroix : could you rebase ?
@krupesh-weboffice : could you test this patch ?

thanks.

[llacroix]

Rebased

[pedrobaeza]

Is this OK? Or should it be closed?

[StefanRijnhart]

Code review, no test.

[pedrobaeza]

Merging this after a while with one verified reviewer and green status.