chore: strip out duplicate implementations of fixed and variable length keys

[TomAFrench]

…th keys

Description

Problem*

Resolves

Summary*

I realised while reviewing #82 that we've got half of the library being duplicated for fixed-length and variable length keys. This PR strips out all of these so that the fixed-length methods just delegate to the variable length methods.

Additional Context

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

ACIR Opcodes

Benchmark suite	Current: 19832cd	Previous: 3a46322	Ratio
get_array_JSON16kb_Bench.json/main	42557 acir_opcodes	42557 acir_opcodes	1
get_array_JSON512b_Bench.json/main	2365 acir_opcodes	2365 acir_opcodes	1
get_keys_at_root_JSON16kb_Bench.json/main	3349896 acir_opcodes	3349896 acir_opcodes	1
get_keys_at_root_JSON512b_Bench.json/main	3334024 acir_opcodes	3334024 acir_opcodes	1
get_literal_JSON16kb_Bench.json/main	17711 acir_opcodes	17711 acir_opcodes	1
get_literal_JSON512b_Bench.json/main	1839 acir_opcodes	1839 acir_opcodes	1
get_number_JSON16kb_Bench.json/main	17838 acir_opcodes	17838 acir_opcodes	1
get_number_JSON512b_Bench.json/main	1966 acir_opcodes	1966 acir_opcodes	1
get_object_JSON16kb_Bench.json/main	42557 acir_opcodes	42557 acir_opcodes	1
get_object_JSON512b_Bench.json/main	2365 acir_opcodes	2365 acir_opcodes	1
get_string_JSON16kb_Bench.json/main	42695 acir_opcodes	42695 acir_opcodes	1
get_string_JSON512b_Bench.json/main	26823 acir_opcodes	26823 acir_opcodes	1
get_value_JSON16kb_Bench.json/main	20188 acir_opcodes	20188 acir_opcodes	1
get_value_JSON512b_Bench.json/main	4316 acir_opcodes	4316 acir_opcodes	1
key_exists_JSON16kb_Bench.json/main	18077 acir_opcodes	18077 acir_opcodes	1
key_exists_JSON512b_Bench.json/main	2205 acir_opcodes	2205 acir_opcodes	1
parse_json_from_string_JSON16kb_Bench.json/main	1098668 acir_opcodes	1098668 acir_opcodes	1
parse_json_from_string_JSON512b_Bench.json/main	38179 acir_opcodes	38179 acir_opcodes	1

This comment was automatically generated by workflow using github-action-benchmark.

[github-actions]

Circuit Size

Benchmark suite	Current: 19832cd	Previous: 3a46322	Ratio
get_array_JSON16kb_Bench.json/main	54968 circuit_size	54968 circuit_size	1
get_array_JSON512b_Bench.json/main	5848 circuit_size	5848 circuit_size	1
get_keys_at_root_JSON16kb_Bench.json/main	3380422 circuit_size	3380422 circuit_size	1
get_keys_at_root_JSON512b_Bench.json/main	3354628 circuit_size	3354628 circuit_size	1
get_literal_JSON16kb_Bench.json/main	32183 circuit_size	32183 circuit_size	1
get_literal_JSON512b_Bench.json/main	6389 circuit_size	6389 circuit_size	1
get_number_JSON16kb_Bench.json/main	32612 circuit_size	32612 circuit_size	1
get_number_JSON512b_Bench.json/main	6883 circuit_size	6883 circuit_size	1
get_object_JSON16kb_Bench.json/main	54968 circuit_size	54968 circuit_size	1
get_object_JSON512b_Bench.json/main	5848 circuit_size	5848 circuit_size	1
get_string_JSON16kb_Bench.json/main	252831 circuit_size	252831 circuit_size	1
get_string_JSON512b_Bench.json/main	227999 circuit_size	227999 circuit_size	1
get_value_JSON16kb_Bench.json/main	35344 circuit_size	35344 circuit_size	1
get_value_JSON512b_Bench.json/main	9550 circuit_size	9550 circuit_size	1
key_exists_JSON16kb_Bench.json/main	31277 circuit_size	31277 circuit_size	1
key_exists_JSON512b_Bench.json/main	9452 circuit_size	9452 circuit_size	1
parse_json_from_string_JSON16kb_Bench.json/main	1473490 circuit_size	1473490 circuit_size	1
parse_json_from_string_JSON512b_Bench.json/main	68763 circuit_size	68763 circuit_size	1

This comment was automatically generated by workflow using github-action-benchmark.

[github-actions]

Brillig Bytecode Size

Benchmark suite	Current: 19832cd	Previous: 3a46322	Ratio
get_array_JSON16kb_Bench	18479 opcodes	18475 opcodes	1.00
get_array_JSON512b_Bench	2607 opcodes	2603 opcodes	1.00
get_keys_at_root_JSON16kb_Bench	43657 opcodes	43657 opcodes	1
get_keys_at_root_JSON512b_Bench	27784 opcodes	27784 opcodes	1
get_literal_JSON16kb_Bench	22319 opcodes	22316 opcodes	1.00
get_literal_JSON512b_Bench	6446 opcodes	6443 opcodes	1.00
get_number_JSON16kb_Bench	22628 opcodes	22625 opcodes	1.00
get_number_JSON512b_Bench	6755 opcodes	6752 opcodes	1.00
get_object_JSON16kb_Bench	18478 opcodes	18475 opcodes	1.00
get_object_JSON512b_Bench	2606 opcodes	2603 opcodes	1.00
get_string_JSON16kb_Bench	24433 opcodes	24430 opcodes	1.00
get_string_JSON512b_Bench	8560 opcodes	8557 opcodes	1.00
get_value_JSON16kb_Bench	23483 opcodes	23480 opcodes	1.00
get_value_JSON512b_Bench	7610 opcodes	7607 opcodes	1.00
key_exists_JSON16kb_Bench	18129 opcodes	18129 opcodes	1
key_exists_JSON512b_Bench	2257 opcodes	2257 opcodes	1
parse_json_from_string_JSON16kb_Bench	16913 opcodes	16913 opcodes	1
parse_json_from_string_JSON512b_Bench	16903 opcodes	16903 opcodes	1

This comment was automatically generated by workflow using github-action-benchmark.