[tools][manifest_compiler] Improve error messages

If the input to the manifest compiler is not valid JSON, format
the location of the error in a format that many tools can directly
understand. Use f-strings to succinctly format all error messages
in read_json_config_file.

Bug: None
Test: test_manifest_compiler.py
Change-Id: I7cc180bdc4deec985508f6a2e1c926e21b9e7c6b
1 file changed