Refactor edit placement system specs

[Kizr]

Context

We have agreed as a team that we'd like to pursue a new style of system specs to bring our organically (home baked) system specs in line and identify any gaps in their testing.

Changes proposed in this pull request

• Adds a system spec for a school user editing a placement for a primary school
• Adds a system spec for a school user editing a placement for a secondary school
• Adds a system spec for a school user editing a placement with no mentors
• Adds a system spec for a school user editing a placement with no providers
• Adds a system spec for a support user editing a placement for a primary school
• Adds a system spec for a support user editing a placement for a secondary school
• Adds a system spec for a support user editing a placement with no mentors
• Adds a system spec for a support user editing a placement with no providers
• Removes redundant edit placement spec for school users
• Removes redundant edit placement spec for support users
• Adds govuk tag matcher

Guidance to review

• Review the spec files and look for any missed scenarios or elements that are important to an end user.

Link to Trello card

Refactor edit placement system tests

[JamieCleare2525]

I think, because pages just the check your answers, show, preview, etc. contain the same information, it's worth adding a current_path to steps checking the page you are on.

[Kizr]

I think, because pages just the check your answers, show, preview, etc. contain the same information, it's worth adding a current_path to steps checking the page you are on.

All of these pages are unique when you factor in the headings, page titles and selected navigation so there's no risk of us falsely identifying the wrong page.

A user generally doesn't care about the URL of the page so long as they're being shown what they expect to be shown, so I do not think of it as a user need and therefore it's not a responsibility of our system specs.

I also don't want to tie our system specs to certain routes in case we need to change those routes in the future, we would have broken tests that still offer the same user journey and therefore should not be breaking.