chore: Migrate read only methods to immutable references

[vezenovm]

Description

Problem*

Should assist in the compiler in preventing unnecessary clones

Summary*

Use immutable methods wherever applicable.

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]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Brillig Bytecode Size'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.01.

Benchmark suite	Current: 5d1a20e	Previous: 00d4360	Ratio
assert_is_not_equal_BLS12_377Fq_Bench	116 opcodes	110 opcodes	1.05
assert_is_not_equal_BLS12_377Fr_Bench	103 opcodes	97 opcodes	1.06
assert_is_not_equal_BLS12_381Fq_Bench	116 opcodes	110 opcodes	1.05
assert_is_not_equal_BLS12_381Fr_Bench	103 opcodes	97 opcodes	1.06
assert_is_not_equal_BN254_Fq_Bench	103 opcodes	97 opcodes	1.06
assert_is_not_equal_U2048_Bench	198 opcodes	192 opcodes	1.03
assert_is_not_equal_U256_Bench	105 opcodes	99 opcodes	1.06
assert_is_not_zero_BLS12_377Fq_Bench	78 opcodes	75 opcodes	1.04
assert_is_not_zero_BLS12_377Fr_Bench	71 opcodes	68 opcodes	1.04
assert_is_not_zero_BLS12_381Fq_Bench	78 opcodes	75 opcodes	1.04
assert_is_not_zero_BLS12_381Fr_Bench	71 opcodes	68 opcodes	1.04
assert_is_not_zero_BN254_Fq_Bench	71 opcodes	68 opcodes	1.04
assert_is_not_zero_U2048_Bench	178 opcodes	175 opcodes	1.02
assert_is_not_zero_U256_Bench	73 opcodes	70 opcodes	1.04
assert_is_not_zero_integer_BLS12_377Fq_Bench	69 opcodes	66 opcodes	1.05
assert_is_not_zero_integer_BLS12_377Fr_Bench	63 opcodes	60 opcodes	1.05
assert_is_not_zero_integer_BLS12_381Fq_Bench	69 opcodes	66 opcodes	1.05
assert_is_not_zero_integer_BLS12_381Fr_Bench	63 opcodes	60 opcodes	1.05
assert_is_not_zero_integer_BN254_Fq_Bench	63 opcodes	60 opcodes	1.05
assert_is_not_zero_integer_U2048_Bench	153 opcodes	150 opcodes	1.02
assert_is_not_zero_integer_U256_Bench	63 opcodes	60 opcodes	1.05
cmp_BLS12_377Fq_Bench	291 opcodes	285 opcodes	1.02
cmp_BLS12_377Fr_Bench	251 opcodes	245 opcodes	1.02
cmp_BLS12_381Fq_Bench	291 opcodes	285 opcodes	1.02
cmp_BLS12_381Fr_Bench	251 opcodes	245 opcodes	1.02
cmp_BN254_Fq_Bench	251 opcodes	245 opcodes	1.02
cmp_U256_Bench	251 opcodes	245 opcodes	1.02
is_zero_BLS12_377Fq_Bench	80 opcodes	77 opcodes	1.04
is_zero_BLS12_377Fr_Bench	71 opcodes	68 opcodes	1.04
is_zero_BLS12_381Fq_Bench	80 opcodes	77 opcodes	1.04
is_zero_BLS12_381Fr_Bench	71 opcodes	68 opcodes	1.04
is_zero_BN254_Fq_Bench	71 opcodes	68 opcodes	1.04
is_zero_U2048_Bench	190 opcodes	187 opcodes	1.02
is_zero_U256_Bench	70 opcodes	67 opcodes	1.04
is_zero_integer_BLS12_377Fq_Bench	64 opcodes	61 opcodes	1.05
is_zero_integer_BLS12_377Fr_Bench	58 opcodes	55 opcodes	1.05
is_zero_integer_BLS12_381Fq_Bench	64 opcodes	61 opcodes	1.05
is_zero_integer_BLS12_381Fr_Bench	58 opcodes	55 opcodes	1.05
is_zero_integer_BN254_Fq_Bench	58 opcodes	55 opcodes	1.05
is_zero_integer_U2048_Bench	148 opcodes	145 opcodes	1.02
is_zero_integer_U256_Bench	58 opcodes	55 opcodes	1.05
sqrt_U2048_Bench	64 opcodes	61 opcodes	1.05
sqrt_U256_Bench	49 opcodes	46 opcodes	1.07
to_be_bytes_BLS12_377Fq_Bench	251 opcodes	248 opcodes	1.01
to_be_bytes_BLS12_377Fr_Bench	201 opcodes	198 opcodes	1.02
to_be_bytes_BLS12_381Fq_Bench	251 opcodes	248 opcodes	1.01
to_be_bytes_BLS12_381Fr_Bench	201 opcodes	198 opcodes	1.02
to_be_bytes_BN254_Fq_Bench	201 opcodes	198 opcodes	1.02
to_be_bytes_U2048_Bench	201 opcodes	198 opcodes	1.02
to_be_bytes_U256_Bench	209 opcodes	206 opcodes	1.01
to_le_bytes_BLS12_377Fq_Bench	294 opcodes	291 opcodes	1.01
to_le_bytes_BLS12_377Fr_Bench	244 opcodes	241 opcodes	1.01
to_le_bytes_BLS12_381Fq_Bench	294 opcodes	291 opcodes	1.01
to_le_bytes_BLS12_381Fr_Bench	244 opcodes	241 opcodes	1.01
to_le_bytes_BN254_Fq_Bench	244 opcodes	241 opcodes	1.01
to_le_bytes_U2048_Bench	241 opcodes	238 opcodes	1.01
to_le_bytes_U256_Bench	252 opcodes	249 opcodes	1.01
validate_in_range_BLS12_377Fq_Bench	80 opcodes	77 opcodes	1.04
validate_in_range_BLS12_377Fr_Bench	70 opcodes	67 opcodes	1.04
validate_in_range_BLS12_381Fq_Bench	80 opcodes	77 opcodes	1.04
validate_in_range_BLS12_381Fr_Bench	70 opcodes	67 opcodes	1.04
validate_in_range_BN254_Fq_Bench	70 opcodes	67 opcodes	1.04
validate_in_range_U2048_Bench	220 opcodes	217 opcodes	1.01
validate_in_range_U256_Bench	70 opcodes	67 opcodes	1.04

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

[jfecher]

Execution reports from #268 look good