PR 32097

Added image and pdf extraction.

Facts and todos:

* Need to add TCA definitions
* This uses PHP functions only, no support for third party tools
* This extracts the most common exif and ipct data from images
* Currently no support for XMP data
* Think about normalizing city and country codes by using static_* data
* ZendPdf seems to be very picky about PDFs and is no longer maintained,
	but I  found no good alternative (except pdfpasrer but its about 30mb)

We could squash some commits to have a nicer merge late ron. Please give some feedback!
Not a blocker for this patch but as of 6.2, TYPO3 CMS is Composer aware (well... work in progress) and something to be tested whether CMS would be already capable to cope if we include a dependency to Zend in the composer.json of Metadata. The Zend Package would / should be then downloaded in Packages/Libraries from the Document Root...