Function get_valid_view_path

Automatic lookup for view in either app view folder or shared view folder. return null if folder not exist

Parameters summary
`string`	`$view_path = ''`	(passed in view name. e.g layouts.bootstrap)
`boolean`	`$searchCurrentAppViewFirstThenSharedView = true`	( choose if you preferred searching app view folder first or shared view folder)

Return value summary
`null\|string`	null\|string