perf(l1): rebuild_bloom - insert instead of merge

[Arkenan]

Merging layer filters is very costly due to the cost of iterating the elements of a filter. Inserting has proven to be cheaper for the size of the filter we're using and the amount of elements we are holding. Some measurements:

• Early hoodi imports went from 8 blocks per second to about 80 (10x).
• Synced hoodi rebuild time went from ~166ms to ~27ms, (about a 6x).

The PR also simplifies the rebuild code and avoids using rayon entirely.

[github-actions]

Lines of code report

Total lines added: 0
Total lines removed: 18
Total lines changed: 18

Detailed view

+-------------------------------------------+-------+------+
| File                                      | Lines | Diff |
+-------------------------------------------+-------+------+
| ethrex/crates/storage/trie_db/layering.rs | 165   | -18  |
+-------------------------------------------+-------+------+

[github-actions]

Benchmark Block Execution Results Comparison Against Main

Command	Mean [s]	Min [s]	Max [s]	Relative
base	59.159 ± 0.194	58.966	59.519	1.00
head	59.347 ± 0.239	58.977	59.733	1.00 ± 0.01