Implement Equinix Metal LoadBalancer support

[displague]

What problem are you facing?

I want to interact with the BETA Load Balancer services via Metal CLI.
https://deploy.equinix.com/developers/docs/metal/networking/load-balancers/

How could the Equinix Metal CLI help solve this problem?

Implement it.

Adds support for the BETA loadbalancer service: https://deploy.equinix.com/developers/docs/metal/networking/load-balancers/

https://github.com/equinix/lbaas-api-docs

Used Project as the base. Lots of cleanup ahead.

TODO:

• Get LB
• List LB
• Detele LB
• Update LB
• Create Project LB
  • Get Pool
  • List Pools
  • Delete Pool
  • Update Pool
  • Create Project Pool
    • Get Origin
    • List Origins
    • Delete Origin
    • Update Origin
    • Create Pool Origin
  • Get LB Port
  • List LB Ports
  • Delete LB Port
  • Update LB Port
  • Create LB Port
• Send debug transport to token exchange when debugging?
• Ensure command docs are correct
• Ensure requirement checks are correct
• Ensure example commands are correct
• Ensure command is named "loadbalancer-beta"
• generate docs

[displague]

This work would benefit from a published Equinix Metal LoadBalancer SDK for Go.

The one that was included in #454 is autogenerated and has been kept in internal/ to prevent reuse and dependency.
A result of this is that it bulks up the metal-cli project.