[IMP] digest: organise digest view

Purpose
=======

Give the user a more organized view of the digest KPIs in the backend and
improve global wording of digest sections and KPIs.

Specifications
==============

Reorganize order of KPIs in digest view. Fix some typos, move buttons in
list and form views.

Task-2582128

closes odoo/odoo#77507

Related: odoo/enterprise#21340
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>