WIP: Add HAProxy ingress controller support to theia-cloud Helm chart

[jfaltermeier]

• Add default HAProxy ingress annotations and class name handling
• Add ingress path suffix helper and pass it to the operator
• Use controller-specific path suffix in service and landing page ingress templates

eclipse-theia/theia-cloud#464

[jfaltermeier]

One remark, the ($|(/.*)) to (/|$)(.*) change in the nginx pattern matches the delimiter and the path as separate groups.
This was an initial attempt to reuse this regexp for HAProxy as well, but in the end it works differently there. I still think this matching makes more sense, so I kept it in.

[jfaltermeier]

Some documentation about new annotations:

https://haproxy-ingress.github.io/docs/configuration/keys/#ssl-redirect
https://haproxy-ingress.github.io/docs/configuration/keys/#proxy-body-size
https://haproxy-ingress.github.io/docs/configuration/keys/#timeout
https://haproxy-ingress.github.io/docs/configuration/keys/#configuration-snippet
https://haproxy-ingress.github.io/docs/configuration/keys/#path-type