*: website

The style to achieve the chess-like bg result was duplicated at many
places. The 'web' app was also actually using an image from the
'web_editor' app (we can live with it in stable as web_editor always
comes with web in auto_install but this was still a mistake).

closes odoo/odoo#54154

Also: fix some layout issue in the colorpicker widget.
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

* web, website_event, website_sale, sale_quotation_builder

Instead of an ugly danger-colored badge promoting "odoo", we now use
the official odoo logo. The code is also refactored to use more
consistent and translatable sentences without duplicated code.

Note: the odoo logo is added in the repo, downloaded from our official
brand assets page (https://www.odoo.com/page/brand-assets), in its
'tiny' version. The repo already contained multiple odoo logos but they
are quite old and should be replaced in a further update. Note: the svg
version was not able to be used as it contains external margins...

Part of https://github.com/odoo/odoo/pull/34422
task-2026299

When the user has not set any image, it now displays the default
user image placeholder instead of the image placeholder in livechat.

Task-ID 1924666

closes odoo/odoo#30821

Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

- Redesign all mimetype icons
- use SVG to reduce file size and improve rendering quality.
- Add a data attribute to attachments to detect the file extension (in somes
  cases just mimetype is not accurate)

The goal is to better see the image can be edited and to have a bigger
image to use in website pages (like a product page).

We would like to make the "no item found" screens more appealing.

Before this commit, it shows a small help tip in the top-left
corner of the screen, just below the "Create" button.

With this commit, these help tips have been replaced by onboarding
screens, which consist of a picture and some text below, both of which
are horizontally centered.

The texts have been slightly changed, so that they are shorter and clearer.

Considered modules:

(A)
    account,
    account_asset,
    account_budget,
    account_test,
    account_voucher,
    analytic
(B)
    barcodes,
    base,
    base_automation,
    board
(C)
    calendar,
    contacts,
    crm
(D)
    delivery
(E)
    event
(F)
    fleet
(G)
    gamification,
    google_drive
(H)
    hr,
    hr_attendance,
    hr_contract,
    hr_expense,
    hr_gamification,
    hr_holidays,
    hr_payroll,
    hr_recruitment,
    hr_timesheet
(I)
    im_livechat
(L)
    l10n_fr_sale_closing,
    link_tracker,
    lunch
(M)
    mail,
    maintenance,
    mass_mailing,
    membership,
    mrp
(N)
    note
(P)
    payment,
    point_of_sale,
    post_mercury,
    pos_restaurant,
    product,
    project,
    purchase,
    purchase_requisition
(R)
    rating,
    repair,
    resource
(S)
    sale,
    sale_timesheet,
    sales_team,
    stock,
    stock_account,
    stock_landed_costs,
    stock_picking_batch,
    survey
(U)
    utm
(W)
    web,
    website,
    website_blog,
    website_customer,
    website_event_track,
    website_forum,
    website_quote,
    website_sale,
    website_sale_digital,
    website_slides

Add 3 pictures to illustrate empty states across several modules.
Width 120px,  variable height.

This commit introduces the 'rainbowification' feature to the web client
(and to some affected addons).  This feature is essentially a way to
display a nice friendly message when some business event happens.  For
example, a encouraging message is displayed when the user clear her/his
inbox, or when a salesman closes a deal.

The mechanism currently only displays a 'rainbowman', but could be
extended later to add other kind of animation.

There are a few different ways to display a 'rainbowman':
- any JS code can simply trigger_up an event ('show_effect') with some
  options: for example
    this.trigger_up('show_effect', {
        type: 'rainbow_man',
        fadeout: 'no',
        message: $done,
        click_close: false,
    });
- an action returned by the server can have an 'effect' key, with some
  options
- the do_execute_action method accepts a 'effect' option.  This is
  useful when one wants to specify a rainbow on an action button in a
  form view

Joint work with: dbh <dbh@odoo.com>, ged <ged@odoo.com>

Avoid duplicating web addon in enterprise by extracting a common basis.
Enterprise features stay in enterprise, but use that common basis.

Mainly:
 - JS refactoring and linting
 - Conversion of .sass into .less split into multiple files
 - Templates cleaning and DOM simplification
 - Re-generation of web.pot, and update of .po files