Add Stroke Width Transform algorithm for Text Detection
* added SWTTextDetection code
* remove warnings from opencv_text compilation
* added bib for SWT Text Detection
* resolve initial pr suggestions
* change file name according to convention
* added optional OutputArray
* removed bug related to letter candidature
* added unit tests for stroke width transform text detection
* Added demo program
* made all minor edits required
* corrected findDataFilePath and removed manual allocation
* Added ArgumentParser
* corrected typo
* remove headers not allowed
* correct test case
* corrected float typecast warnings and test case
* remove final double correction and problematic test case
* test(swt): coding style
* finalminor bug corrections
