fix: telemetry data field

[moliholy]

This PR fixes the data field in the JSON payload, which must be an object and not a string. Since I was on it, I also improved debug logs for telemetry.

[codecov]

Codecov Report

❌ Patch coverage is 61.11111% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.92%. Comparing base (565e5f0) to head (7d9044c).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/pop-telemetry/src/lib.rs	61.11%	4 Missing and 3 partials ⚠️

@@            Coverage Diff             @@
##             main     #719      +/-   ##
==========================================
- Coverage   76.92%   76.92%   -0.01%     
==========================================
  Files         111      111              
  Lines       25234    25239       +5     
  Branches    25234    25239       +5     
==========================================
+ Hits        19412    19414       +2     
- Misses       3763     3767       +4     
+ Partials     2059     2058       -1     

Files with missing lines	Coverage Δ
crates/pop-telemetry/src/lib.rs	85.85% <61.11%> (-1.19%)	⬇️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.