Align with job family, greenhouse & org structure.

Why is this change being made?

The hiring details had a few outdated details or duplicated information already on the job family page.

This edit serves to:

• update the language to align with the job family,
• deduplicate what is in the job family page to ensure a SSOT,
• align the titles of interviews with the language used in Greenhouse and sent to candidates,
• clarify participants from Customer Support at each stage,
• state the requirement for at least one interviewer at panel interview to be non-male
• update role names to align with current Customer Support organization structure.

What this edit does NOT yet address (MR to come)

• review guidelines of how to perform assessments of technical questionnaires
• updating location of artefacts for assessments and technical interviews.

Marked as draft to get input from Support Ops to ensure this applies equally to support ops hiring practices.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the "Maintained by" section in on the page being edited.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies.
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files. (this requirement has been removed pending identification of a new DRI for the handbook)