#219 Tests: add new search order tests in CALL.testGroup

[Josep Maria Blasco]

Added test_search_order_2 thru 7. All the tests are done against the caller's ("same") directory, the current directory, and the only directory in PATH (manually set).

• 2: normal tests, e.g. "test.rex". They all work under 5.0.0.
• 3: downward-relative tests, e.g. "lib/test.rex". They all work under 5.0.0.
• 4: dot-relative paths, e.g. "./test.rex". Only the current-directory-relative test passes.
• 5: dotdot-relative paths, e.g., "../test.rex". Only the current-directory-relative test passes.
• 6 (Windows only) : backslash-relative paths, e.g., "\some\path\test.rex". Only the current-directory-relative test passes.
• 7 (Windows only): drive-relative paths, e.g., "D:some\path\test.rex". Only the current-directory-relative test passes.

Tested under Windows 11 and Ubuntu 22.04.

[Josep Maria Blasco]

Updated version. Remove created files and directories manually (leaving it to uninit is unreliable), and correct some typos.

[Josep Maria Blasco]

Sorry. Sent without attaching. Here it is.