Move web_terminal_spec E2E test to CE folder

What does this MR do and why?

Describe in detail what your merge request does and why.

Web Terminal for IDE feature was moved to Core in #211685 (closed), we need to move the test and relevant page objects to reflect that. Also removes the comment about not running the test in relative_url jobs as it is no longer relevant (it was fixed by !70355 (merged)).

Once this is merged, I will also remove Enterprise Edition labels from the test results and failure issues.

First task of https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1007

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Please note that the test is currently in quarantine due to #338179 (closed). To test on local run:

BROWSER_HEADLESS=false QA_DEBUG=true  bundle exec bin/qa Test::Instance::All http://[localhost/your IP address]:3000/ -- qa/specs/features/browser_ui/3_create/web_ide/web_terminal_spec.rb --tag quarantine

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.