Add a `nginxprocess` package for working with NGINX processes #4595

Job	Run time
Performance Tests	4m 51s
Lint	3m 50s
Build Unsigned Snapshot	1m 54s
Unit tests with race condition detection	2m 31s
Unit Tests	2m 1s
Integration Tests (ubuntu, 22.04)	9m 1s
Integration Tests - Official OSS Images	0s
Integration Tests - Official Plus Images	0s
Integration Tests (redhatenterprise, 9)	8m 35s
Load Tests	0s
Integration Tests (alpine, 3.19)	6m 16s
Publish NGINX Agent v3 packages	0s
	38m 59s

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