Feat(Inventory): Basic auth for Agent

[MyvTsv]

Checklist before requesting a review

Please delete options that are not relevant.

• I have read the CONTRIBUTING document.
• I have performed a self-review of my code.
• I have added tests that prove my fix is effective or that my feature works.

Description

Implement Basic Auth form for inventory endpoint

Screenshots (if appropriate):

[stonebuzz]

$DB->commit() should not be used
I was able to check that the configuration had been saved correctly

[cconard96]

I think there should be a warning displayed when trying to use basic authentication. It really should never be used, except as a short-term solution for anyone that was handling this at the web server level previously until they are able to switch to using OAuth.

[trasher]

I think there should be a warning displayed when trying to use basic authentication. It really should never be used, except as a short-term solution for anyone that was handling this at the web server level previously until they are able to switch to using OAuth.

If we warn about using an unsecure auth mechanism, we have to warn about using default no auth at all one. I wonder if a better place would be in documentation.