feat: add string formatter to `ak.Array.show` #1737

Job	Run time
MacOS (3.12)	2m 9s
Windows (3.12, x64)	2m 25s
MacOS (3.11)	4m 36s
Linux (3.12, -r requirements-test.txt)	2m 45s
Windows (3.11, x64)	3m 38s
Linux (3.11, -r requirements-test.txt)	4m 5s
MacOS (3.10)	5m 12s
Windows (3.10, x64)	3m 37s
Linux (3.10, -r requirements-test.txt)	3m 56s
MacOS (3.9)	4m 55s
Windows (3.9, x64)	5m 19s
Linux (3.9, -r requirements-test.txt)	3m 50s
MacOS (3.8)	4m 47s
Windows (3.8, x64)	6m 0s
Linux (3.8, -r requirements-test.txt)	5m 29s
Windows (3.9, x86)	5m 1s
Linux (3.8, -r requirements-test-minimal.txt)	1m 38s
Linux-ROOT-dask-awkward (3.8)	4m 7s
	1h 13m 29s

Provide feedback