feat: return deleted config in delete config response

[GurtejSohi]

Description

We need to return the deleted config value in DeleteConfigResponse

Testing

Updated unit test and integration tests

Checklist:

• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• Any dependent changes have been merged and published in downstream modules

[codecov]

Codecov Report

Merging #41 (e2e6f31) into main (0202b63) will decrease coverage by 0.10%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##               main      #41      +/-   ##
============================================
- Coverage     90.90%   90.80%   -0.11%     
- Complexity      109      111       +2     
============================================
  Files            14       14              
  Lines           418      424       +6     
  Branches         18       19       +1     
============================================
+ Hits            380      385       +5     
  Misses           32       32              
- Partials          6        7       +1     

Flag	Coverage Δ
integration	90.80% <100.00%> (-0.11%)	⬇️
unit	88.88% <100.00%> (+1.79%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...pertrace/config/service/ConfigServiceGrpcImpl.java	84.09% <100.00%> (+1.16%)	⬆️
...race/config/service/store/DocumentConfigStore.java	98.78% <0.00%> (-1.22%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0202b63...e2e6f31. Read the comment docs.

[github-actions]

Unit Test Results

10 files  ±0  10 suites  ±0   9s ⏱️ -1s
33 tests +1  33 ✔️ +1  0 💤 ±0  0 ❌ ±0 

Results for commit 496cb66. ± Comparison against base commit 0202b63.