chore(rln): further refactoring of interface

[rymnc]

Refactored the conditional compilation and import statements in the circuit.rs and updated method signatures to improve code clarity. Also, updated error handling in function vk_from_raw for better legibility.

[github-actions]

Benchmark for 049c601

Click to view benchmark

Test	Base	PR	%
FullMerkleTree::compute_root	0.0±0.00ns	0.0±0.00ns	NaN%
FullMerkleTree::delete	848.1±29.31ns	851.3±22.13ns	+0.38%
FullMerkleTree::get	0.0±0.00ns	0.0±0.00ns	NaN%
FullMerkleTree::get_empty_leaves_indices	7.4±0.11ns	7.5±0.25ns	+1.35%
FullMerkleTree::get_subtree_root	0.9±0.02ns	0.9±0.01ns	0.00%
FullMerkleTree::override_range	1316.2±23.71ns	1311.3±20.01ns	-0.37%
FullMerkleTree::set	841.9±7.78ns	850.3±12.70ns	+1.00%
OptimalMerkleTree::compute_root	1009.8±9.55ns	1040.3±118.34ns	+3.02%
OptimalMerkleTree::delete	1006.6±20.06ns	1022.7±14.79ns	+1.60%
OptimalMerkleTree::get	24.0±0.93ns	23.7±0.19ns	-1.25%
OptimalMerkleTree::get_empty_leaves_indices	7.1±0.04ns	7.2±0.56ns	+1.41%
OptimalMerkleTree::get_subtree_root	24.4±0.37ns	24.3±0.33ns	-0.41%
OptimalMerkleTree::override_range	4.2±0.08µs	4.2±0.10µs	0.00%
OptimalMerkleTree::set	1006.8±29.86ns	1022.6±26.47ns	+1.57%

[github-actions]

Benchmark for 049c601

Click to view benchmark

Test	Base	PR	%
FullMerkleTree::::full_height_gen	15.5±0.65ms	15.4±0.11ms	-0.65%
OptimalMerkleTree::::full_height_gen	574.7±8.34µs	568.1±6.26µs	-1.15%
Pmtree::compute_root	0.0±0.00ns	0.0±0.00ns	NaN%
Pmtree::get	339.2±4.99ns	337.5±4.60ns	-0.50%
Pmtree::get_empty_leaves_indices	8.7±0.16ns	8.7±0.18ns	0.00%
Pmtree::get_subtree_root	486.6±7.44ns	480.9±22.58ns	-1.17%
Pmtree::override_range	236.2±7.51µs	240.7±3.28µs	+1.91%
Pmtree::set	53.6±1.01µs	58.2±0.87µs	+8.58%
Pmtree:delete	53.7±0.64µs	61.4±1.19µs	+14.34%
Set/FullMerkleTree::::set/1	552.7±19.33µs	544.2±7.25µs	-1.54%
Set/FullMerkleTree::::set/10	5.6±0.02ms	5.4±0.06ms	-3.57%
Set/FullMerkleTree::::set/100	55.7±0.20ms	54.8±0.10ms	-1.62%
Set/FullMerkleTree::::set_range/1	552.7±7.43µs	544.4±6.19µs	-1.50%
Set/FullMerkleTree::::set_range/10	756.6±3.14µs	745.6±4.69µs	-1.45%
Set/FullMerkleTree::::set_range/100	3.3±0.01ms	3.3±0.01ms	0.00%
Set/OptimalMerkleTree::::set/1	560.7±7.11µs	544.0±9.38µs	-2.98%
Set/OptimalMerkleTree::::set/10	5.6±0.01ms	5.5±0.01ms	-1.79%
Set/OptimalMerkleTree::::set/100	56.0±0.44ms	55.0±0.28ms	-1.79%
Set/OptimalMerkleTree::::set_range/1	557.6±8.91µs	543.7±5.64µs	-2.49%
Set/OptimalMerkleTree::::set_range/10	5.6±0.02ms	5.4±0.02ms	-3.57%
Set/OptimalMerkleTree::::set_range/100	55.7±0.18ms	54.8±0.15ms	-1.62%
vk::vk_from_ark_serialized	1513.7±13.67ns	1508.7±15.40ns	-0.33%
zkey::zkey_from_raw	3.3±0.01s	3.3±0.01s	0.00%

[seemenkina]

LGTM