Update the docs to use new policies in place of the legacy ones

[bartsmykla]

Description

In all places where the docs were using legacy policies to suggest some behavior or to show examples we should replace it with the new policies instead.

• docs(meshtrafficpermission): added information about mesh traffic per… #1607
• docs(policies): added references for target ref policies #1608
• docs(dataplane-health): update with new policies #1613
• Update Networking / Non-mesh traffic page with new policies - @slonka docs(networking): convert non-mesh traffic doc to use targetref policies #1615
  • Use MeshProxyPatch instead of ProxyTemplate
• @michaelbeaumont Update/Replace Explore / Gateway page with new policies
  • WIP docs(managing-ingress): rewrite Gateway page to Managing Ingress Traffic #1582
• docs(inspect-api): update page to show new policies #1614
• @slonka - docs(mesh): convert policy references to targetref ones for 2.6 #1618 - Update Kuma in Production / Create multiple service meshes in a cluster page with new policies
  • Link to new policies
  • Replace TrafficRoute from the example with new policies

[slonka]

I'll take

Update [Networking / Non-mesh traffic](https://kuma.io/docs/dev/networking/non-mesh-traffic/) page with new policies
Use MeshProxyPatch instead of ProxyTemplate