Using flask-login request_loader, we can validate jwt tokens.
This allows to use the same decorators for the web UI (using cookies)
and the API (using JWT) as well as the current_user local proxy.

JIRA INFRA-412

Allow to enter Ansible variables on host in YAML format.
Use codemirror (http://codemirror.net) to make editing YAML easier.

JIRA INFRA-412

Use the before_flush hook to trigger the core services update.
It's much nicer than having to call a method in several places.

The core services update is triggered on creation/modification/deletion
of an Interface.

In the before_flush we can manipulate the session (add objects) but we
shouldn't call commit.
The db.session.commit() was removed from the launch_task method.

https://black.readthedocs.io/en/stable/

Add new jinja2 filter to format datetime

This is to be used for stack of switches only

- a stack_member is linked to an host (device_type has to be "Switch")
- a stack_member is an integer between 0 and 9 (included) or can be None
- the couple (host_id, stack_member) must be unique

JIRA INFRA-267

The sorting of the models was done in the utils.get_model_choices
funtion but a specific query was passed to not display admin_only networks.

The sorting is now done even when passing a specific query to
get_model_choices.

JIRA INFRA-284

- create many-to-many relationships between the user table and
attributes tables (manufacturer / model / location / status / action)
- add a checkbox as the first column of the attributes table to add or
remove an attribute to the favorites
- add a new page to display the favorite attributes

JIRA INFRA-283

Fix error:
User instance is not bound to a Session; attribute refresh operation cannot proceed

The network range defines the IP to be allocated.
This is to reserve some specific addresses (for gateway for example).

An admin user should be able to define an interface outside the network
range.

The IP address select field was replaced with a string field
(initialized to the first available IP).

Fixes INFRA-200

Fixes INFRA-197

Pagination information (next, prev, first, last) is included in the Link
HTTP header.
The total number of entries is provided in the X-Total-Count HTTP
header.

Strings are automatically converted to datetime object.
Note that datetime are stored without timezone in the database (in UTC).

- This will help tracking who and what was created / changed
- Move fetch_current_user_id to utils.py
- Make ItemComment inherit from CreatedMixin

When registering a new host, only admin users shall be able to select
networks marked as "admin_only"

If a selectfield is disabled, None is returned (not a string).
To pass wtforms validation, that value shall be part of the choices.

We use None as the value for SelectField that are optional (instead of
'').
We were previously converting '' to None when creating a model.
We now use the coerce function to let the form convert 'None' to None.

Can use:

  -  /api/items?serial_number=123456
  -  /api/items?location_id=1

This can be done via the Admin interface but this latter shall be
restricted to admin users. This simple page allows the group "create"
to easily add new Manufacturer, Model or Location.

The serial number might not be unique and can't be used
as the string to hash.
There are for example SD cards that all have the same SN.

Using an ICS id allows to pre-print labels that can be assigned to
hardware when scanning serial numbers.
This id shall be easy to remember (unlike UUID).

The hash is supposed to be computed in the __init__ method of Item.
But flask-admin never passes any parameter when creating the model class.
The attributes are changed after creation.

When creating an item in the admin view, we use the on_model_change
method to update the hash.

There might be a better way to avoid this code duplication.
This works for now.