Problem

Based on #2075 and #2069,

• there is tight coupling between the reliability logic and the LightPush SDK class
• if a lightpush.send() request fails, we renew the peer directly

Solution

Based on the above problem statement, we want to do two things:

• extend and separate reliability related logic into a separate class apart from LightPush (SenderMessageMonitor)
• attempt retries on the failed peers for lightpush.send() before we actually renew the peer

Notes

• Resolves feat(lightpush): add retries to failing peers #2069
• Resolves feat: message verification and retry #2075 partially
• To be merged after feat(filter): reliability monitor as a separate class to handle reliability logic #2117 (with rebase)

Contribution checklist:

• covered by unit tests;
• covered by e2e test;
• add ! in title if breaks public API;