[IMP] quickstart: add an argument and config to avoid cloning the repository automatically

[lse-odoo]

Description

Locally running custom python code from an unknown author is a security risk. Users willing to easily download a database dump and restore it cannot currently do it in one command (would need to use dump then restore) which is inconvenient.

Introducing a new parameter for quickstart command called --toggle_clone_repo that will override the default quickstart behavior of always pulling the instance GitHub repository.

As certain users would rarely need to clone database custom code, we also introduced a configuration parameter:
toggle_clone_repo in (quickstart section) to avoid cloning the repository. If the config parameter is not set (so, the default behavior) is to always download the custom code

Adding --toggle_clone_repo will negate the config value.

Example:

• User A: "I generally want to have databases repository custom code" ->
  odev quickstart <db>
  "but sometime not" ->
  odev quickstart --toggle_clone_repo <db>
• User B: "I generally don't want to have the database custom code" -> first set the config
  odev config quickstart.should_clone_repo False (on the first time only!) then
  odev quickstart <db>
  "but this time I want the custom code" ->
  (assuming he already ran odev config quickstart.should_clone_repo False):
  odev quickstart --toggle_clone_repo <db>

Linked Issues

None

Compliance

• I have read the contribution guide
• I made sure the documentation is up-to-date both in doctrings and the docs directory
• I have added or modified unit tests where necessary (there is none on quickstart :( )
• I have added new libraries to the requirements.txt file, if any
• I have incremented the version number according the versioning guide
• The PR contains my changes only and no other external commit

[lse-odoo]

@brinkflew may I have your opinion on the idea please ? If your are okay with it I'll see if I can add tests etc.
One point on which I am very skeptical is the call to Config() in the default value computation. I like the idea like this so that the value is always overridable despite the config value if given explicitly in the command line

[brinkflew]

@sea-odoo is also looking at implementing a "no dump" feature for this command so I think there is something at play here