Rename regression tests with descriptive file names #19105

(I vaguely remember there was a similar issue but could not find it..if it is a duplicate, please leave a pointer, thanks!)

There are currently a couple of tests named test-regress-* and many of them are referring to really old regressions in the v0.x repo. I think it's time to rename them with something more descriptive now.

• test/sequential/test-regress-GH-1697.js
• test/sequential/test-regress-GH-1726.js
• test/sequential/test-regress-GH-4015.js
• test/sequential/test-regress-GH-4027.js
• test/sequential/test-regress-GH-784.js
• test/sequential/test-regress-GH-877.js
• test/parallel/test-regress-GH-1531.js
• test/parallel/test-regress-GH-2245.js
• test/parallel/test-regress-GH-3238.js
• test/parallel/test-regress-GH-3542.js
• test/parallel/test-regress-GH-3739.js
• test/parallel/test-regress-GH-4256.js
• test/parallel/test-regress-GH-4948.js
• test/parallel/test-regress-GH-5051.js
• test/parallel/test-regress-GH-5727.js
• test/parallel/test-regress-GH-5927.js
• test/parallel/test-regress-GH-6235.js
• test/parallel/test-regress-GH-9819.js
• test/parallel/test-regress-GH-io-1068.js
• test/parallel/test-regress-GH-io-1811.js
• test/parallel/test-regress-GH-node-9326.js

cc @nodejs/collaborators