Wrapper scripts in /opt/puppetlabs/bin should ensure /opt/puppetlabs/bin is on the PATH

The puppet-agent package provides wrapper scripts in /opt/puppetlabs/bin that serve as the entrypoint to the Puppet and PE CLI. Currently, these wrappers unset environment variables like LD_LIBRARY_PATH that affect where the linker looks for shared libraries. We should extend the wrappers to also ensure /opt/puppetlabs/bin/ is on the PATH.

If /opt/puppetlabs/bin/ is missing from the PATH, external Puppet subcommandsl, like puppet-infra will show up as not found. This is usually handled by bash profile scripts installed by the puppet-agent package, but these are sometimes ignored:

$ ls /opt/puppetlabs/bin/puppet-infra

/opt/puppetlabs/bin/puppet-infra

$ sudo /opt/puppetlabs/bin/puppet infra configure

Error: Unknown Puppet subcommand 'infra'

See 'puppet help' for help on available puppet subcommands