types: support find package/import all usage for Go Modules or GOPATH.
types: support find package/import all usage for Go Modules or GOPATH.

- check has Go Modules skip runtime.GOROOT(), GOROOT go.mod named std/pkg etc.  - add findPackageDef for lookup package define use ast.File
- add findPackageImports for lookup package import use ast.File
- add findPackageUses for lookup package used use types.PkgName.Imported()
- merge LookupName,LookupImport to LookupObjects func and refactor same code.
- ObjKind add ObjPackage indicate "package xxx", org ObjPkgName indicate "import xxx"
- add new flags -import_range indicate export import range, syntax filename:line:column1-column2:

visualfc/gotools,visualfc/gotools