feat: ConnectionManager extends EventEmitter & exposed on the Waku interface (& minor improvements)

[danisharora099]

Problem

We recently introduced a method on the ConnectionManager class to fetch the discovered/connected peers tagged by their discovery protocols, and also made it an EventEmitter. However, there is no way to access the class currently.

Solution

This PR adds ConnectionManager on the Waku interface, making it easy to access it simply using waku.connectionManager.xyz()

This PR also improves the public/private accessors, and refactors the test file to use the new API.

[github-actions]

size-limit report 📦

Path	Size	Loading time (3g)	Running time (snapdragon)	Total time
Waku core	30.26 KB (0%)	606 ms (0%)	2.2 s (+2.26% 🔺)	2.8 s
Waku Simple Light Node	235.43 KB (0%)	4.8 s (0%)	5.7 s (-13.49% 🔽)	10.5 s
ECIES encryption	28.54 KB (0%)	571 ms (0%)	1.2 s (-34.58% 🔽)	1.8 s
Symmetric encryption	28.55 KB (0%)	571 ms (0%)	2.3 s (+26.79% 🔺)	2.9 s
DNS discovery	108.36 KB (0%)	2.2 s (0%)	3.6 s (+12.33% 🔺)	5.8 s
Privacy preserving protocols	122.73 KB (0%)	2.5 s (0%)	3.7 s (+4.53% 🔺)	6.1 s
Light protocols	31.72 KB (0%)	635 ms (0%)	2.1 s (+75.97% 🔺)	2.8 s
History retrieval protocols	30.94 KB (0%)	619 ms (0%)	1.9 s (+5.64% 🔺)	2.5 s
Deterministic Message Hashing	5.78 KB (0%)	116 ms (0%)	772 ms (-5.42% 🔽)	887 ms