WIP: Report aggregated time for directories and files

[nickrobinson251]

before

julia> using ReTestItems; runtests("test/packages/TestOnlyDeps.jl/")
  Activating project at `~/repos/ReTestItems.jl/test/packages/TestOnlyDeps.jl`
┌ Warning: The project dependencies or compat requirements have changed since the manifest was last resolved.
│ It is recommended to `Pkg.resolve()` or consider `Pkg.update()` if necessary.
└ @ Pkg.API ~/repos/rai-julia/usr/share/julia/stdlib/v1.10/Pkg/src/API.jl:1807
[ Info: Scanning for test items in project `TestOnlyDeps` at paths: test/packages/TestOnlyDeps.jl/
[ Info: Finished scanning for test items in 0.52 seconds.
[ Info: Scheduling 2 tests on pid 56765
20:54:50 | START (1/2) test item "use a test-only dep" at test/deps_tests.jl:1
20:54:50 | DONE  (1/2) test item "use a test-only dep" <0.1 secs (89.4% compile), 59.86 K allocs (4.582 MB)
20:54:50 | START (2/2) test item "deps as expected" at test/deps_tests.jl:6
20:54:50 | DONE  (2/2) test item "deps as expected" <0.1 secs (58.7% compile), 7.00 K allocs (526.320 KB)
[ Tests Completed: 2/2 test items were run.
Test Summary:             | Pass  Total  Time
TestOnlyDeps              |    2      2  0.4s
  test                    |    2      2
    test/deps_tests.jl    |    2      2
      use a test-only dep |    1      1  0.1s
      deps as expected    |    1      1  0.0s

after

julia> using ReTestItems; runtests("test/packages/TestOnlyDeps.jl/")
  Activating project at `~/repos/ReTestItems.jl/test/packages/TestOnlyDeps.jl`
[ Info: Scanning for test items in project `TestOnlyDeps` at paths: test/packages/TestOnlyDeps.jl/
[ Info: Finished scanning for test items in 0.54 seconds.
[ Info: Scheduling 2 tests on pid 53254
20:53:43 | START (1/2) test item "use a test-only dep" at test/deps_tests.jl:1
20:53:43 | DONE  (1/2) test item "use a test-only dep" <0.1 secs (89.8% compile), 59.86 K allocs (4.582 MB)
20:53:43 | START (2/2) test item "deps as expected" at test/deps_tests.jl:6
20:53:43 | DONE  (2/2) test item "deps as expected" <0.1 secs (55.8% compile), 7.00 K allocs (526.320 KB)
[ Tests Completed: 2/2 test items were run.
Test Summary:             | Pass  Total  Time
TestOnlyDeps              |    2      2  0.4s
  test                    |    2      2  0.1s    # <--
    test/deps_tests.jl    |    2      2  0.1s    # <--
      use a test-only dep |    1      1  0.1s
      deps as expected    |    1      1  0.0s