Add support for unmanaged kubernetes

[vishesh92]

Update APIs with latest main. Depends on apache/cloudstack#7515

displaytext was made not required for a couple of APIs because of which there might be some breaking changes.

[rohityadavcloud]

ping @vishesh92 is this up to date?

[vishesh92]

@rohityadavcloud Updated the PR. We can make an alpha release of cloudstack-go. The version would be v2.16.0-alpha.

You can specify pre-release versions by appending a hyphen and dot separated identifiers (for example, v1.0.1-alpha or v2.2.2-beta.2). Normal releases are preferred by the go command over pre-release versions, so users must ask for pre-release versions explicitly (for example, go get example.com/[email protected]) if your module has any normal releases.
Source: https://go.dev/blog/publishing-go-modules

[rohityadavcloud]

LGTM