remove redudant use of os.walk and check pageTitles are actually created properly

[WolfgangFahl]

check an example for a pageTitle with a "/" or other directory separating characters depending on os

make sure the two methods:
cmdline.py:

 @staticmethod
    def getPageTitlesForWikiTextPath(backup_path:str)->list:
        '''
        get the page titles for the given backupPath
        
        Args: 
            backup_path(str): the path to the WikiText Files (e.g. created by wikibackup)
            
        Returns:
            list: a list of PageTitles
        '''       
        page_titles = []
        if backup_path:
            for path, _subdirs, files in os.walk(backup_path):
                for name in files:
                    filename = os.path.join(path, name)[len(backup_path) + 1:]
                    if filename.endswith(".wiki"):
                        page_titles.append(filename[:-len(".wiki")])
        return page_titles;

wikiFileManager.py

def getAllWikiFiles(self,wikiTextPath:str=None):
        '''
        get all wiki Files for the given wikiTextPath

        Args:
            wikiTextPath(str): the root of the wikiText directory (e.g. a wikiBackup target or staging area for generating or fixing/restoring wikiMarkup)

        Returns:
            dict: a lookup for WikiFiles by pageTitle
        '''
        allWikiFiles = {}
        if wikiTextPath is None:
            wikiTextPath=self.wikiTextPath
        for root, _dirnames, filenames in os.walk(wikiTextPath):
            for filename in filenames:
                if filename.endswith('.wiki'):
                    wikiFile=WikiFile(filename, wikiFileManager=self)
                    allWikiFiles[wikiFile.getPageTitle()]=wikiFile
        return allWikiFiles

are integrated