and remove some unnecessary code

In the tests environmnent, we don't want img and iframe nodes to
perform RPCs when they are inserted into the DOM. For img nodes,
we prefixed the src attribute by '#test: ' as soon as they were
inserted into the DOM. Unfortunately, this didn't work as expected:
an RPC was done to fetch route '/web/tests?' (i.e. the tests page),
because everything after '#' in the url isn't sent to the server.

This rev. completely removes the src attribute of img nodes, and
set a 'data-src' attribute with the original src attribute's value,
so that it can still be checked in the tests.

Tests using this attribute have been adapted accordingly.

... instead of hacking test_utils.

In left menu used for switching between "apps" particular menu, the
apps names were not translated.

This commit use the "string" attribute which is translated instead of
"data-string" fallbacking on data-string (so things still work without
updating the module).

opw-781728
closes #20972

Purpose
=======

Settings are often way too long and hard to scan and sometimes you don't know where to find the settings you're looking for.
By adding a left navigation, you can already have an overview of the settings, and switch easily between them.

Specification
=============

- Add a search bar on all the apps that have settings which can search results from all the installed apps.
  (If i'm on sales settings,and I search anything then it shows results from sales settings and also shows
  all the other matching results from all the other apps such as, Inventory...etc) with app name.
- Able to activate feature from the current page results (no matter if the searched result is from another apps).
- Highlight searched word in results
- Delete the sheet, have a full white background
- Add left navigation bar on setting
- Left navigation bar fixed
- List displayed based on installed apps
- On right panel, by default display current app setting and change accordingly
- [Mobile] Left navigation bar displayed on top
- Add Breadcrumb on top of the page: have the name "Settings" + Save / discard CTA + Search
- Add General Settings on the nav bar
- remove "save this page..." notif in all settings
- Delete all recommanded apps section + all checkbox that install app should disappear:
	payroll: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrSkMzWVpuZ0ZoaFE/view?usp=drivesdk
	Events: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrYXlHMHd2NTM2blE/view?usp=drivesdk
	Manufacturing: Delete Repair - Quality Control - Maintenance - Product Lifecycle Management [LAP][ok]
	Timesheets: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrdFg5XzNydkd2TlU/view?usp=drivesdk
	project: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrraWo3NE04TktwcTQ/view?usp=drivesdk
	inventory: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrQkRaVUR5ekFQYTQ/view?usp=drivesdk
	recruitment: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrbDdqLWQweF80UkE/view?usp=drivesdk
	purchase: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrRlAyUDBnb0trQWs/view?usp=drivesdk
	email marketing: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrOUZONjhvX2k3Y2s/view?usp=drivesdk
	expenses: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrrR0JpN1ZpQmtxU3M/view?usp=drivesdk
	attendances: https://drive.google.com/a/odoo.com/file/d/0B1uIL9E_zXrralpjZ1VJclNpMWs/view?usp=drivesdk
- About duplicate settings:
	Docsaway: Delete from Sales + delete Default Print Provider
	Attributs & Variants: Delete from Purchases - Manufacturing
	Multi-currencies: delete from Sales
	Unit Of Measures: Delete from Purchase & Expenses
- Add a scroll bar on the left bar when there's too many apps
- Keep the navbar visible even when you search
- Move General Settings to the bottom of the list
- Update on Settings:
    - Accounting:
        - rename automatic rates
        - Anglo Saxon Account: Should be in technical feature
        - Place Accounting Reports section before Taxes section
    - CRM:
        - Phone Validation: Enforce international format becomes
        - Local Numbers: (2 radio buttons proposals) Add international prefix / No prefix
    - Fleet: typo " ... a new car if ..." + text is too long <br>
    - project: fix tooltip for colab pads