[FW][IMP] sale_gathering: add icon to show stock available

[fw-bot-adhoc]

Forward-Port-Of: #1126

[roboadhoc]

Pull request status dashboard.

[fw-bot-adhoc]

@lef-adhoc @matiasperalta1 cherrypicking of pull request #1126 failed.

stdout:

Auto-merging sale_gathering/views/sale_order_views.xml
CONFLICT (content): Merge conflict in sale_gathering/views/sale_order_views.xml
Auto-merging sale_gathering/models/sale_order_line.py
Auto-merging sale_gathering/i18n/es.po
CONFLICT (content): Merge conflict in sale_gathering/i18n/es.po
Auto-merging sale_gathering/__manifest__.py
CONFLICT (content): Merge conflict in sale_gathering/__manifest__.py

stderr:

17:10:34.250764 git.c:444               trace: built-in: git cherry-pick e67dd8ae8dd3d34d47da961b9a4f54b600c3bc5f
error: could not apply e67dd8ae... [IMP] sale_gathering: add icon to show stock available
hint: after resolving the conflicts, mark the corrected paths
hint: with 'git add <paths>' or 'git rm <paths>'
hint: and commit the result with 'git commit'
----------
status:

Either perform the forward-port manually (and push to this branch, proceeding as usual) or close this PR (maybe?).

In the former case, you may want to edit this PR message as well.

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port