better argument names for StringContains #7469

Job	Run time
Check Debug build	4m 25s
LPython CI (3.10, ubuntu-latest)	8m 48s
Build LPython to WASM	6m 3s
LPython CI (3.10, macos-latest)	12m 37s
Test CPython Interop (@pythoncall)	3m 29s
LPython CI (3.10, windows-2019)	12m 18s
Run Integration tests with Python 3.9	3m 30s
Check Release build	6m 21s
Run Integration tests with Python 3.10	3m 20s
Run SymPy tests	3m 58s
Run Integration tests with Python 3.11	3m 22s
Test LLVM 10	4m 16s
Run Integration tests with Python 3.12	3m 27s
Test LLVM 15	4m 28s
Test PIP Installable Packages	3m 9s
Test LLVM 16	4m 30s
Upload Tarball	36s
Build Jupyter Kernel	3m 31s
	1h 32m 8s

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