Remove requirement of -go-package from typeshare with go feature

[MOmarMiraj]

Currently the typeshare CLI with go feature enabled, doesn't allow the usage of package in typeshare.toml as the CLI requires the --go-package to be there. This MR will tackle that issue by not requiring the --go-package.

I also added a check to ensure that the package name is passed as this is a requirement in Golang.

I also added a UT for reading the package name from a typeshare.toml