refactor: webhook notifier re-design

[isSerge]

Summary

Closes #283

Mostly refactoring here:

• Remove discord, slack and telegram notifiers
• Remove Notifier trait
• Introduce PayloadBuilder trait that encapsulates logic to format message and build JSON for a specific channel
• Introduce AsWebhookComponents trait for TriggerTypeConfig to consolidate all logic to create webhook config, choose payload builder, etc.
• Fix payload serialization issue described in Re-design Webhook notifier(s) #283

Testing Process

• add Network configuration
• add Trigger configuration with Telegram, Discord, Slack or generic Webhook
• add Monitor configuration (default big USDC transfer will do) and include above triggers
• run monitor: cargo run

Checklist

• Add a reference to related issues in the PR description.
• Add unit tests if applicable.
• Add integration tests if applicable.
• Add property-based tests if applicable.
• Update documentation if applicable.

[codecov]

Codecov Report

❌ Patch coverage is 93.38843% with 40 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.2%. Comparing base (b6301aa) to head (fbddb5b).
⚠️ Report is 14 commits behind head on main.

Files with missing lines	Patch %	Lines
src/services/notification/email.rs	69.7%	23 Missing ⚠️
src/services/notification/mod.rs	95.9%	9 Missing ⚠️
src/services/notification/webhook.rs	89.8%	6 Missing ⚠️
src/services/notification/payload_builder.rs	99.2%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #314     +/-   ##
=======================================
- Coverage   96.3%   96.2%   -0.1%     
=======================================
  Files         78      76      -2     
  Lines      25229   24771    -458     
=======================================
- Hits       24308   23847    -461     
- Misses       921     924      +3     

Flag	Coverage Δ
integration	59.9% <51.5%> (-1.5%)	⬇️
properties	30.0% <2.3%> (-1.4%)	⬇️
unittests	86.1% <91.9%> (-0.3%)	⬇️

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[shahnami]

Thanks @isSerge 🥇

The code LGTM, I just need to test it, I'll get it done by EOW.

[NicoMolinaOZ]

LGTM!
I have tested all channels, working well.

[shahnami]

LGTM, thanks for testing Nico