Add a `nginxprocess` package for working with NGINX processes #4501

Job	Run time
Build Unsigned Snapshot	1m 51s
Performance Tests	4m 45s
Unit tests with race condition detection	2m 29s
Unit Tests	2m 8s
Lint	3m 45s
Integration Tests (ubuntu, 22.04)	8m 24s
Integration Tests (redhatenterprise, 9)	7m 17s
Integration Tests (alpine, 3.19)	5m 40s
Integration Tests - Official OSS Images	0s
Integration Tests - Official Plus Images	0s
Load Tests	0s
Publish NGINX Agent v3 packages	0s
	36m 19s

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