Migrate DB Manager args to be managed by environment variables

[caiofralmeida]

After opening a PR parameterizing the DB manager's listen-address via ARGs, @andreyvelich suggested that we standardize all component configurations in environment variables since we have several configurations present, see docs.

The idea is to move the listen-address and connect-timeout arguments to environment variables, update documentation, and make a deprecation notice for the new version.

[tenzen-y]

/kind feature

[caiofralmeida]

@tenzen-y could you please assign this issue to me? I would like to implement it :)

[tenzen-y]

@tenzen-y could you please assign this issue to me? I would like to implement it :)

Thank you for your help. Feel free to take this issue with /assign comment.

[caiofralmeida]

/assign

[andreyvelich]

Thank you for creating this @caiofralmeida!
Should we directly migrate Katib DB Manager config to Katib Config as part of this work: https://www.kubeflow.org/docs/components/katib/user-guides/katib-config/?
E.g. we should have a new section like:

init:
  dbManager:
    ....

We discussed before that we want to have unify config to control all Katib system settings to simplify user experience.

I understand that it is more work, but we don't need to rush with the implementation.
WDYT @caiofralmeida @tenzen-y @Electronic-Waste ?