Before this commit, Odoo used checkboxes in three different ways:
- A simple <input type="checkbox"/>, mainly in the frontend. The style
is browser dependant.
- Same as above but with the BS3, checkbox structure. The style is still
the same, but the alignement is supposed to be better (which is not
always the case).
- The Odoo official structure:
```
<div class="o_checkbox">
<input type="checkbox"/>
<span/>
</div>
```
which allows to have a cross-browser checkbox style and correct
alignements.
The goal after this commit is to only use the BS4 *custom* checkbox
structure to achieve the same goal as our official structure (and
remove that one):
```
<div class="custom-control custom-checkbox">
<input type="checkbox" class="custom-control-input" id="customCheck1">
<label class="custom-control-label" for="customCheck1">...</label>
</div>
```
/!\ Labels are now required (use a zero-width space if necessary)
qsm-odoo
f4fbaf1efa