Implement request identity

[slinkydeveloper]

Fix #278

[github-actions]

Test Results

 46 files  +1   46 suites  +1   2m 43s ⏱️ +9s
641 tests ±0  632 ✅ ±0  9 💤 ±0  0 ❌ ±0 
642 runs  +1  633 ✅ +1  9 💤 ±0  0 ❌ ±0 

Results for commit 91df1fb. ± Comparison against base commit 9718851.

This pull request removes 8 and adds 8 tests. Note that renamed tests count towards both.

dev.restate.sdk.common.CoreSerdesTest ‑ Byte: 105
dev.restate.sdk.common.CoreSerdesTest ‑ Double: 0.07072016453844021
dev.restate.sdk.common.CoreSerdesTest ‑ Float: 0.05527097
dev.restate.sdk.common.CoreSerdesTest ‑ Integer: -983196108
dev.restate.sdk.common.CoreSerdesTest ‑ Long: 7013535649422325739
dev.restate.sdk.common.CoreSerdesTest ‑ Short: -25468
dev.restate.sdk.common.CoreSerdesTest ‑ byte[]: [B@68044f4
dev.restate.sdk.serde.jackson.JacksonSerdesTest ‑ [Till, Francesco]

RestateRequestIdentityVerifierTest ‑ parseKey()
dev.restate.sdk.common.CoreSerdesTest ‑ Byte: 98
dev.restate.sdk.common.CoreSerdesTest ‑ Double: 0.28447023151784057
dev.restate.sdk.common.CoreSerdesTest ‑ Float: 0.57615143
dev.restate.sdk.common.CoreSerdesTest ‑ Integer: -1668576129
dev.restate.sdk.common.CoreSerdesTest ‑ Long: -5310028650171459088
dev.restate.sdk.common.CoreSerdesTest ‑ Short: 2564
dev.restate.sdk.common.CoreSerdesTest ‑ byte[]: [B@256f8274

♻️ This comment has been updated with latest results.

[jackkleeman]

I'm no Java expert but the implementation looks correct to me! Thank you