These tags are either part of the baseline specification or included by
default by GIMP when exporting TIFF files. Note that we don't add
support for them in the decoder yet. This commit only allows us to parse
the metadata and display it gracefully.
When the `TIFF_DEBUG` flag is set, the TIFF decoder logs every tag and
their values. This is already useful but require the developer to have
the spec handy in order to decrypt each value to its signification. None
of this information is available at runtime, but this is known by the
Python generator. So by generating these debug logs, we drastically
increase their value.
As a bonus point, most of these functions should be useful when we will
display image's metadata in Serenity.
The `TIFFType` enum is exported with a different name to C++. This
change of behavior was handled by manually setting the parameter of a
function. However, we will soon need the exported name in more places,
so let's make it a property of the Enum itself.
Only some specific number of values should be allowed, but let's accept
everything for now and add these checks when the generator will be more
mature.
This tag type is a bit different as even if it fits in the general
definition given in the TIFF specification. That is the value will be of
one specified type multiplied by a known count. Having a
`Vector<Variant<u8, ...>>` will be very painful to use. So let's deviate
a bit from the normal way and use a `ByteBuffer` directly instead this
complicated type.
This will allow us to generate code that handle and provide easy access
to metadata stored in TIFF's tags. The generator is a Python script, and
it output both TIFFMetadata.h and TIFFTagHandler.cpp files.
The generator will definitely need some update to support all TIFF and
EXIF tags, but that will still be easier than writing everything
ourselves.
Some small modifications are needed in TIFFLoader.cpp to make it
compatible with the new `Metadata` class.
