Upload aws images and metadata

This MR contains:

• upload images and metadata after build stage to aws
• build stage is no longer executed after upgrade stage, but after any pushed commit. This way, upgrade stage (scheduled) will autocommit if any there are any changes. Autocommit will trigger the build, and the build will correspond with the current state of pv-manifest (pv manifest versionm, git sha and git time)
• new environment stage to retrieve pipeline metadata (pv manifest version, git sha, commit time and pvr version). Triggered by pushed commit before build
• build creates now image metadata for each architecture (ph revision)
• new x64-uefi arch build
• simplified build per architecture. One job per arch for latest and stable (optional)
• commented script