After this commit, the user will be able to clone a question
inside a survey, the cloned question will have the same sequence
as the original and thus will be displayed just below it.
This commit also remove the is_conditional icon on the overall
questions tree view and the misplaced warning which was
previously introduced in commit [1].
[1] : b1d1856245
Task-3088848
closesodoo/odoo#112385
X-original-commit: bdcc2e6c4bec23c200a3fa2a2b4dd1bb06943f39
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>