[common] Dont load fixed middlewares if not found or not enabling treafik integration by default

[PrivatePuffin]

Is your feature request related to a problem?

Currently I think we try-to load fixed-middleware, even if they are not found.
This means our ingress (without disabling the integration code), is inherently not compatible with upstream treafik, which makes it less easy for non-truecharts-centered users to use TrueCharts common in their clusters.

Describe the solution you'd like

Not loading fixed-middlewares if they are not found/present and the treafik namespace is not set.

Describe alternatives you've considered

Not enabling the integration by default.
Which is a serieus option we should consider for compatibility tbh.

Additional context

No response

I've read and agree with the following

• I've checked all open and closed issues and my request is not there.
• I've checked all open and closed pull requests and my request is not there.

[PrivatePuffin]

@stavros-k You wrote most of this, so I've assigned it to your for feedback and convenience.