location: adjust path for editors

[benknoble]

Running "raco test foo/bar/test.rkt" will cause Racket to change directory to "foo/bar" before invoking "test.rkt", and error messages are printed relative to (current-directory) like

raco test: "foo/bar/test.rkt"
--------------------
fail
FAILURE
name:       check-equal?
location:   test.rkt:5:0
actual:     1
expected:   2
--------------------
1/1 test failures

For an editor to consume this, it has to post-process the output to correlate "raco test: path" with "location: partial path" (which is difficult when running tests in parallel). This is not ideal; output with

location:   foo/bar/test.rkt:5:0

is immediately useable by editors for jumping to the error.

Use the new current-test-invocation-directory to adjust the path better for editors, depending on compiler-lib 1.14. The output now looks like

raco test: "foo/bar/test.rkt"
--------------------
fail
FAILURE
name:       check-equal?
location:   foo/bar/test.rkt:5:0
actual:     1
expected:   2
--------------------
1/1 test failures

---

Depends on https://github.com/racket/racket/pull/4988.