Enable Automatic Consul Injection into Windows Workloads

[joselo85]

Changes proposed in this PR:

• Created function to detect pod's OS
• Modified container_init.go and consul_dataplane_sidecar.go to assign values depending on pod's OS.
• Added Windows images fields to MeshWebhook struct in mesh_webhook.go
• Added new flags to inject-connect/command.go to set the Windows images values
• Added the default Windows image values to values.yaml and added the new config flags in connect-injector-deployment.yaml template.
• Created WindowsSupport.md documenting this process.

How I've tested this PR: Built and pushed the required Windows images see this guide
Using helm package command, packaged the modified Consul Helm chart. Created custom values to install the packaged Helm chart. Deployed HashiCorp's counting service in Linux node and dashboard service in Windows node. Both deployments with the annotation to inject Consul.

How I expect reviewers to test this PR: Follow this guide, along with WindowsSupport.md

Checklist:

• [x] Tests added
• [ ] CHANGELOG entry added

  HashiCorp engineers only, community PRs should not add a changelog entry. Entries should use present tense (e.g. Add support for...)

[komapa]

Is this PR planned on being finished? Thank you!