feat: `SSEResponse` class for streaming Server-Side Events #14193

Job	Run time
Setup PHP Version for Code Coverage	4s
Others (8.3) / Sanity Tests	2m 30s
Others (8.2) / Sanity Tests	3m 52s
Others (8.4) / Sanity Tests	2m 39s
Others (8.5) / Sanity Tests	2m 25s
SeparateProcess (8.5) / tests	3m 15s
CacheLive (8.2) / Cache Live Tests	2m 23s
SeparateProcess (8.2) / tests	3m 25s
SeparateProcess (8.4) / tests	3m 30s
DatabaseLive (8.2, OCI8, 8.0) / tests	7m 36s
CacheLive (8.4) / Cache Live Tests	2m 8s
DatabaseLive (8.2, MySQLi, 8.0) / tests	5m 6s
CacheLive (8.3) / Cache Live Tests	2m 12s
DatabaseLive (8.3, MySQLi, 8.0) / tests	4m 39s
DatabaseLive (8.2, Postgre, 8.0) / tests	3m 10s
DatabaseLive (8.3, SQLite3, 8.0) / tests	2m 26s
DatabaseLive (8.3, OCI8, 8.0) / tests	6m 52s
DatabaseLive (8.5, OCI8, 8.0) / tests	7m 2s
DatabaseLive (8.5, SQLSRV, 8.0) / tests	5m 58s
SeparateProcess (8.3) / tests	3m 32s
CacheLive (8.5) / Cache Live Tests	2m 10s
DatabaseLive (8.4, MySQLi, 8.0) / tests	4m 42s
DatabaseLive (8.5, MySQLi, 8.0) / tests	4m 44s
DatabaseLive (8.5, SQLite3, 8.0) / tests	2m 56s
DatabaseLive (8.3, Postgre, 8.0) / tests	2m 58s
DatabaseLive (8.4, OCI8, 8.0) / tests	7m 18s
DatabaseLive (8.3, SQLSRV, 8.0) / tests	5m 46s
DatabaseLive (8.5, Postgre, 8.0) / tests	2m 43s
DatabaseLive (8.4, SQLSRV, 8.0) / tests	6m 8s
DatabaseLive (8.2, SQLite3, 8.0) / tests	2m 38s
DatabaseLive (8.2, SQLSRV, 8.0) / tests	6m 12s
DatabaseLive (8.4, SQLite3, 8.0) / tests	2m 11s
DatabaseLive (8.4, Postgre, 8.0) / tests	2m 40s
DatabaseLive (8.2, MySQLi, 5.7) / tests	4m 6s
Upload coverage results to Coveralls / coveralls	50s
	2h 12m 46s

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