feat(io.__init__.py): adds support for topcon fda files (#12)

* NF: add basic support for fda files

* refactor(main-and-io-module-__init__-files): specify topcon as vendor in fda import function

* feat(io.__init__.py): add bscan metadata to returned eye volume

before the fda reader only parsed bscans and segmentation. These changes incorporate scaling and bscan position in fundus images.

* feat(io.__init__.py): add fundus image to eyevolume

the changes allow to create a full EyeVolume with fundus image and metadata

* style(io.__init__.py): remove double quotes

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Co-authored-by: Olivier Morelle <Oli4@users.noreply.github.com>