[16.0][IMP] session_db: Modify the way to parse data from session data

[JonathanOsAlc]

Description of the issue/feature this PR addresses:

Current behaviour before PR:

• When the session has a key with a binary value and uses the session_db module, it triggers an error because the binary value can't be written to the database of session_db.
• Also, it trigger error when the value is int or float and Odoo wants to render that value as monetary.
• And when using debug in the URL parameter and the value is a number, for example: URL?debug=1

Desired behavior after PR is merged:

• Add a way to detect the binary values to parse as strings when saving the session to the database.
  • To identify the data, that was converted from binary to str, add a prefix base64:: to the string.
  • Then when the session needs to be read, detect the values modified, and parse again to base64.
• Also verify if some value of session is a monetary value and parse to float type.
• And keep string type in the value of the 'debug' website parameter.

[OCA-git-bot]

Hi @sbidoul,
some modules you are maintaining are being modified, check this out!

[sbidoul]

Hello and thanks for contributing!

To help me understand your PR, can you elaborate the problem you are addressing? In particular do they also occur with the standard Odoo session or only with session_db? Do they occur with standard Odoo modules or custom code?

Can you also elaborate what the problem with debug=1, as I personally never noticed any problem in debug mode with session_db.