Generators: add tests for handling <standard> element + use consistent encoding cross-PHP #2122

Job	Run time
Build Phar on PHP: 8.0	33s
Coverage: 8.4 (Linux)	4m 49s
Coverage: 8.4 (Win)	1m 40s
Coverage: 5.4 (Linux)	25m 28s
Coverage: 5.5 (Win)	2m 18s
Coverage: 7.2 with custom ini settings (Linux)	5m 51s
PHP: 5.4 (Linux)	1m 21s
PHP: 5.5 (Linux)	7m 19s
PHP: 5.6 (Linux)	5m 45s
PHP: 7.0 (Linux)	1m 32s
PHP: 7.1 (Linux)	1m 26s
PHP: 7.2 (Linux)	1m 20s
PHP: 7.3 (Linux)	51s
PHP: 7.4 (Linux)	54s
PHP: 8.0 (Linux)	50s
PHP: 8.1 (Linux)	51s
PHP: 8.2 (Linux)	1m 10s
PHP: 8.3 (Linux)	1m 12s
PHP: 8.4 (Linux)	34s
PHP: 8.5 (Linux)	1m 35s
PHP: 5.5 (Win)	1m 27s
PHP: 5.6 (Win)	5m 50s
PHP: 7.0 (Win)	1m 26s
PHP: 7.1 (Win)	1m 43s
PHP: 7.2 (Win)	1m 27s
PHP: 7.3 (Win)	1m 5s
PHP: 7.4 (Win)	1m 2s
PHP: 8.0 (Win)	56s
PHP: 8.1 (Win)	56s
PHP: 8.2 (Win)	57s
PHP: 8.3 (Win)	56s
PHP: 8.4 (Win)	34s
PHP: 8.5 (Win)	1m 4s
PHP: 5.5 with custom ini settings (Linux)	6m 49s
PHP: 7.0 with custom ini settings (Linux)	1m 11s
coveralls-finish	5s
	1h 34m 47s

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