[16.0][FIX] authorization

[baringji]

Add scope param in the authorization url when using oauth2.
Fix 'webservice.backend' object has no attribute get_access_action.

[OCA-git-bot]

Hi @etobella,
some modules you are maintaining are being modified, check this out!

[simahawk]

@gurneyalex can you pls review this?
@baringji thanks for your contrib!
Could you please have a look at our commit guidelines.
Namely:

1. drop the odoo version
2. add module name
3. shorten the msg to be more synthetic and relevant and keep further info for the commit description (eg: [FIX] webservice: webservice.backend.get_access_token AttributError

Also, tests need an update very likely :)

[github-actions]

There hasn't been any activity on this pull request in the past 4 months, so it has been marked as stale and it will be closed automatically if no further activity occurs in the next 30 days.
If you want this PR to never become stale, please ask a PSC member to apply the "no stale" label.

[santostelmo]

@gurneyalex I think this fix make sense. The scope should be passed as parameter