Fix: unique ruleid-testid displayed for unit tests

[Sebitosh]

As discussed in #24

Goes from displaying go-ftw test ids that are based on the MRTS test id (which is repeated and does not allow to understand what exact rule failed) to displaying test ids based on the generated rule matching the generated test. The fix is to place the generated rule's ID earlier in the file name than any other number (in our case the test ID we name our MRTS test files). This fix appends the ruleid at the beginning of the file instead of at the end.

The display goes from:

👉 executing tests in file MRTS_002_ARGS.yaml
	running 2-1: ✔ passed in 12.842548ms (RTT 54.970028ms)
	running 2-2: ✔ passed in 12.049459ms (RTT 54.891019ms)
	running 2-3: ✔ passed in 10.790834ms (RTT 53.365412ms)
	running 2-4: ✔ passed in 10.695786ms (RTT 53.515826ms)
👉 executing tests in file MRTS_002_ARGS.yaml
	running 2-1: ✔ passed in 8.615306ms (RTT 52.334647ms)
	running 2-2: ✔ passed in 7.64326ms (RTT 52.301444ms)
	running 2-3: ✔ passed in 8.353395ms (RTT 52.289161ms)
	running 2-4: ✔ passed in 8.704224ms (RTT 52.993254ms)

To:

👉 executing tests in file MRTS_002_ARGS_A-GET.yaml
	running 100000-1: ✔ passed in 4.03606ms (RTT 51.456201ms)
	running 100000-2: ✔ passed in 2.100709ms (RTT 50.672271ms)
	running 100000-3: ✔ passed in 3.572981ms (RTT 51.673479ms)
	running 100000-4: ✔ passed in 2.85232ms (RTT 50.599715ms)
👉 executing tests in file MRTS_002_ARGS_A-GET.yaml
	running 100001-1: ✔ passed in 2.102875ms (RTT 50.515938ms)
	running 100001-2: ✔ passed in 2.188394ms (RTT 50.675838ms)
	running 100001-3: ✔ passed in 2.013156ms (RTT 50.583605ms)
	running 100001-4: ✔ passed in 1.750534ms (RTT 50.572695ms)
👉 executing tests in file MRTS_002_ARGS_A-GET.yaml
	running 100002-1: ✔ passed in 1.529288ms (RTT 50.430978ms)
	running 100002-2: ✔ passed in 1.516805ms (RTT 50.58156ms)
	running 100002-3: ✔ passed in 1.440502ms (RTT 50.483487ms)
	running 100002-4: ✔ passed in 1.64741ms (RTT 50.50112ms)

And the generated test files are now named:

$ ls

100000_MRTS_002_ARGS_A-GET.yaml          100032_MRTS_004_ARGS_GET.yaml        100064_MRTS_006_ARGS_NAMES_A-GET.yaml
100001_MRTS_002_ARGS_A-GET.yaml          100033_MRTS_004_ARGS_GET.yaml        100065_MRTS_006_ARGS_NAMES_A-GET.yaml
100002_MRTS_002_ARGS_A-GET.yaml          100034_MRTS_004_ARGS_GET.yaml        100066_MRTS_006_ARGS_NAMES_A-GET.yaml
100003_MRTS_002_ARGS_A-GET.yaml          100035_MRTS_004_ARGS_GET.yaml        100067_MRTS_006_ARGS_NAMES_A-GET.yaml
...

[airween]

LGTM.