[FIX] website, *: allow to re-edit company team snippet images

*: website_sale

Since [1], it was not possible to edit a company team snippet image
anymore as soon as the page was saved once. Indeed that commit added
o_not_editable/contenteditable="false" on the parent column to make sure
no text can be added in that column and contenteditable="true" on the
images so that they are still editable (even though HTML-specs-wise
adding contenteditable="true" on images probably does not mean much as
images are self-closing tags, our editor understand that as the ability
to edit the image anyway). That contenteditable="true" part is however
removed when leaving edit mode... and was not restored upon entering
edit mode again.

This fixes the problems with a specific JS patch, we'll review to see if
better can be done in master.

Funny enough, that bug was actually gone in 15.0... by mistake. A recent
bug fix actually reintroduced that isolated bug at [2] (by reintroducing
the fact that images in a non-editable environment are not possible to
edit). The 3 opened tickets this commit mentions were actually reported
for 15.0 immediately after that, while the 14.0 being broken about this
since the beginning apparently did not bother anyone.

Note: as a forward-ported fix, this also takes the opportunity to clean
a bit what was done at [3]. (calling `_super`, no duplicated code,
adding comments, ...).

[1]: https://github.com/odoo/odoo/commit/656cac1bf21c7c5a56aa569008aac58436c747fb
[2]: https://github.com/odoo/odoo/commit/e113bae04a64a8bd341a80736086ab7c25079dd3
[3]: https://github.com/odoo/odoo/commit/e2f7b8fad76dc816b2f6864340d3740446117cdb



opw-3031217
opw-3032482
opw-3035289

closes odoo/odoo#104193

X-original-commit: e7c8fed8
Signed-off-by: Romain Derie (rde) <rde@odoo.com>
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>