update applications endpoint

[cfaur09]

Proposed Changes

• implemented Promise.All when fetching balance from gatewayService for every application
• implemented withTxCount filter to define txCount for every application
• updated specs for applications

How to test

• <api>applications?withTxCount=true -> should return txCount field
• <api>applications -> response should contain balance field

[github-actions]

k6 load testing comparison.
Base Commit Hash: 3868a97
Target Commit Hash: 0c370cf

Metric	Base				Target				Diff
	Avg	Max	90	95	Avg	Max	90	95	Avg	Max	90	95
Nodes	51.45	1404.47	54.52	56.14	47.62	270.07	52.09	53.67	-7.44% ✅	-80.77% ✅	-4.45% ✅	-4.40% ✅
Mex	49.70	127.31	54.46	56.08	47.83	363.44	52.14	53.87	-3.76% ✅	+185.48% 🔴	-4.26% ✅	-3.93% ✅
Blocks	57.45	1268.25	55.09	58.47	55.00	1414.21	52.72	54.63	-4.27% ✅	+11.51% 🔴	-4.30% ✅	-6.57% ✅
Accounts	51.34	1242.05	54.47	56.28	49.03	1234.97	52.21	53.72	-4.49% ✅	-0.57% ✅	-4.15% ✅	-4.55% ✅
Transactions	69.68	5795.68	55.31	58.47	66.52	5809.30	52.98	55.55	-4.53% ✅	+0.24% 🔴	-4.22% ✅	-5.00% ✅
Tokens	50.45	667.73	54.49	56.28	47.67	253.67	52.10	53.74	-5.51% ✅	-62.01% ✅	-4.39% ✅	-4.51% ✅
Pool	50.53	628.38	54.54	56.17	48.55	880.24	52.20	53.86	-3.93% ✅	+40.08% 🔴	-4.29% ✅	-4.12% ✅
Test Run Duration	60008.57				60001.84

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

[bogdan-rosianu]

optional: we could have used POST /address/bulk for fetching the state of more addresses