zcbor_common.h: Refactor state initialization #1526

Job	Run time
Merge tests 2 - Python (3.12) functional tests (Windows)	1m 53s
Merge test 1 - Twister (Windows) (mps2/an521/cpu0 - build only)	8m 30s
Merge tests 2 - Python (3.9) functional tests (Ubuntu)	44s
Merge tests 2 - Python (3.10) functional tests (Ubuntu)	48s
Merge test 1 - Twister (Ubuntu) (native_sim)	3m 53s
Merge tests 3 - Check repo files (Ubuntu)	1m 1s
Merge test 1 - Twister (Ubuntu) (native_sim with asserts)	3m 27s
Merge tests 2 - Python (3.11) functional tests (Ubuntu)	40s
Merge tests 2 - Python (3.12) functional tests (Ubuntu)	51s
Merge test 1 - Twister (Ubuntu) (native_sim/native/64)	3m 29s
Merge test 1 - Twister (Ubuntu) (native_sim/native/64 with asserts)	3m 26s
Merge tests 2 - Python (3.13) functional tests (Ubuntu)	52s
Merge test 1 - Twister (Ubuntu) (mps2/an521/cpu0)	4m 3s
Merge test 1 - Twister (Ubuntu) (mps2/an521/cpu0 with asserts)	4m 15s
Release tests 4 (Python ${{ matrix.python-version }}${{ (((matrix.asserts != '') && ' with asserts') \|\| '') }})	0s
Release tests 1 - Check versions	0s
Release tests 3 (Python ${{ matrix.python-version }}${{ (((matrix.asserts != '') && ' with asserts') \|\| '') }})	0s
Release tests 2 - Fuzz	0s
	37m 52s

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