Replaces eager calls to Test.get_source_location to lazy calls to Frame_Hider.get_top_stack_frame, resulting in a 2x speedup for Base_Tests.

Test utilities wrap their contents in Frame_Hider.hide, and wrap callbacks in Frame_Hider.unhide. These marker frames are used to skip test utility frames to find the real user-level location of the test failure.

The frames_to_skip parameter is no longer needed, since the number of frames to skip is computed dynamically on test failure.

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.
• If meaningful changes were made to logic or tests affecting Enso Cloud integration in the libraries,
  or the Snowflake database integration, a run of the Extra Tests has been scheduled.
  • If applicable, it is suggested to paste a link to a successful run of the Extra Tests.