Ws custom subscriptions

[stefangutica]

Reasoning

• allow users to subscribe to custom fresh txs/events

Proposed Changes

• add 2 new subscription options for fresh txs/events

How to test

• emit subscription to subscribeCustomTransactions and subscribeCustomEvents with appropiate filters. You should receive only new txs/events depending on the filter you put in your subscription payload (check websocket.subscription.cs-e2e.ts for an example

[github-actions]

k6 load testing comparison.
Base Commit Hash: 000bdeb
Target Commit Hash: 7b992d7

Metric	Base				Target				Diff
	Avg	Max	90	95	Avg	Max	90	95	Avg	Max	90	95
Mex	57.29	188.15	62.15	65.56	50.26	152.42	54.04	56.25	-12.28% ✅	-18.99% ✅	-13.05% ✅	-14.21% ✅
Tokens	57.80	622.93	62.18	65.52	50.79	609.70	54.04	56.39	-12.14% ✅	-2.12% ✅	-13.10% ✅	-13.93% ✅
Pool	57.63	728.22	62.26	65.51	50.71	589.40	54.07	56.40	-12.00% ✅	-19.06% ✅	-13.15% ✅	-13.91% ✅
Transactions	73.95	1180.81	63.11	69.01	63.10	993.21	54.85	58.82	-14.67% ✅	-15.89% ✅	-13.09% ✅	-14.76% ✅
Blocks	66.39	916.40	63.30	70.74	57.47	766.30	54.67	58.36	-13.44% ✅	-16.38% ✅	-13.64% ✅	-17.50% ✅
Nodes	57.16	136.59	62.00	65.10	50.52	463.89	54.02	56.20	-11.63% ✅	+239.62% 🔴	-12.87% ✅	-13.68% ✅
Accounts	58.57	1299.19	61.48	65.07	51.34	1072.61	53.93	56.25	-12.35% ✅	-17.44% ✅	-12.27% ✅	-13.56% ✅
Test Run Duration	60001.98				60003.05

Legend: Avg - Average Response Time, Max - Maximum Response Time, 90 - 90th Percentile, 95 - 95th Percentile
All times are in milliseconds.