docs(playwright-engine): add UI and CLI guides and migration recipe #6508

Job	Run time
config-e2e	1s
Build docker image	6m 14s
CLI unit tests	44s
Agent unit tests	1m 20s
WebUI unit tests	1m 58s
API Server unit tests	2m 44s
CLI smoke tests (local)	46s
CLI smoke tests (docker)	40s
Test examples (collector)	39s
CLI e2e tests (8, 0)	1m 30s
WebUI End-to-end tests (1)	2m 37s
Test examples (tracetest-jaeger)	44s
CLI e2e tests (8, 1)	1m 21s
WebUI End-to-end tests (2)	3m 35s
Test examples (tracetest-opensearch)	7m 25s
Tracetesting API Server (InMemory)	3m 55s
CLI e2e tests (8, 2)	1m 25s
WebUI End-to-end tests (3)	2m 29s
Test examples (tracetest-tempo)	41s
CLI e2e tests (8, 3)	1m 25s
WebUI End-to-end tests (4)	2m 36s
Test examples (tracetest-provisioning-env)	39s
CLI e2e tests (8, 4)	1m 22s
WebUI End-to-end tests (5)	2m 28s
Tracetesting API Server (NATS)	3m 57s
CLI e2e tests (8, 5)	2m 34s
WebUI End-to-end tests (6)	2m 37s
CLI e2e tests (8, 6)	1m 24s
WebUI End-to-end tests (7)	2m 30s
CLI e2e tests (8, 7)	3m 40s
WebUI End-to-end tests (8)	2m 31s
	1h 8m 31s

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