add scripts/upgrade-packagespec (#10276)
add scripts/upgrade-packagespec (#10276)

* add scripts/upgrade-packagespec

* upgrade-packagespec script: docs + actionable logs

* upgrade-packagespec script: escape branch name

- This is now more accurate and handles branch names with
  slashes and pluses better.

* Update scripts/upgrade-packagespec

Co-authored-by: Nick Cabatoff <0416004c7a77c0adac464978aca592d70fd881ec@hashicorp.com>

Co-authored-by: Nick Cabatoff <0416004c7a77c0adac464978aca592d70fd881ec@hashicorp.com>
hashicorp/vault,rnaveiras/vault,rnaveiras/vault,hashicorp/vault,hashicorp/vault,rnaveiras/vault,rnaveiras/vault,hashicorp/vault,hashicorp/vault,rnaveiras/vault,hashicorp/vault