Fix PSR class/trait/method naming

[mvorisek]

pure case refactor only, class/trait/method names are CI

renamed to pure PascalCase (camelCase for methods) with snake case reasoning (like you will never write h_t_m_l)

based on (?<!::)(trait|interface|function|class) ((?!(Expression|Connection|Query)_).)*[A-Z][A-Z]

the only breaking change is that these files will not load using autoloaded if not optimized and not using CI FS

updated names:

DIContainerTrait
atk4\core\ExceptionRenderer\HTML
atk4\core\ExceptionRenderer\JSON
Exception::getHTML()
Exception::getJSON()

for 100% BC you can require the renamed classes manually (but if some other updated code required them before use is enough)

[mvorisek]

@georgehristov ok with you, can you approve?

[georgehristov]

For me it follows agreed naming convention so your effort on this is appreciated!