[16.0][ADD] web_action_conditionable: support forms

[hbrunn]

This was supported in v8 but never made it into newer versions.

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Similarly in forms you can write:

<form create="false" delete="false" duplicate="false" edit="false">

and with this module you can do:

<form create="state=='draft'" delete="state!='done'" duplicate="some_field=='some value'" edit="state!='done'">

[hbrunn]

/ocabot rebase

[OCA-git-bot]

Congratulations, PR rebased to 16.0.

[hoangtrann]

@simahawk could you help merge this?