Add "node-map-max" to allow configuring nodemap size.

[tommyp1ckles]

Using the node-map-max flag, one can now override the default 16k node map size.
This may be needed for large clusters, where the number of distinct node IPs in the cluster exceeds the standard size.

In helm, this will allow overriding the size using bpf.nodeMapMax: <size>

[tommyp1ckles]

/test

[tommyp1ckles]

/test

[tommyp1ckles]

/test

[pchaigno]

I think we need documentation in https://docs.cilium.io/en/latest/network/ebpf/maps/#ebpf-maps. A few generated files are also missing but the CI already highlighted it.

[pchaigno]

I'd be in favor of backporting to at least the latest OSS release given without this some users may hit error logs that can't be avoided in any other way.

[tommyp1ckles]

/test

[gandro]

The Helm workflow is failing due to some files not being regenerated (e.g. the values.yaml file), but otherwise this looks good to me.

Make sure to run

make -C install/kubernetes
make -C Documentation update-helm-values

[tommyp1ckles]

/test

[tommyp1ckles]

Looks like quay was done for ci images.

[tommyp1ckles]

/test

[nbusseneau]

@tommyp1ckles This PR depends on changes around the pkg/datapath modularization which were introduced during v1.15 development cycle and not backported to v1.14, I've marked the PR as backport/author for now so you can decide on what to do :)