#3612)

Closes #3349.

Closes #3444.

The inline image abbreviations were previously supported in the
publicly facing `decode_stream_data` function. Doing some analysis
showed that this support was limited:

  * Our own code would always map to the "proper" names beforehand, thus
    we possibly never tested this variant and it has been incomplete.
  * Only abbreviations for the filter names were supported. Already
    using `/F` instead of `/Filter` for the filter names itself or
    specifying `/DP` instead of `/DecodeParams` would fail, as well as
    all other keys from table 91 and 92 of the PDF 2.0 specification.

With this in mind, only external API users might have used this API in
the full manner, although we never seem to have received specific
reports about the not supported/mapped parameters. Thus, deprecating the
abbreviations specific to inline images in this generic function seems
like the best way to move forward.

While I was working on this to analyze the current behavior, I wrote
some basic inline image tests for the previously unsupported filter
abbreviations CCF and DCT (at least in `decode_stream_data`). The new
abbreviations were added for completeness (although deprecated
directly), showing that using `PageObject.images` never errored out or
would run into the deprecation now due to proper mapping in our own
code.

)

Closes #3534.

Closes #3372.

Additionally improves readability and avoids unnecessary exception handling, as well as some side effects due to shadowing variable names in the affected methods which were refactored.

… Core Font Metrics (#3606)

---------

Co-authored-by: Stefan <96178532+stefan6419846@users.noreply.github.com>

Includes some additional refactoring of test utilities.

Closes #3622.

Fixes #3628

…t widget annotations (#3624)

We used to overwrite a text appearance stream's resource dictionary
when we initiated it from an annotation. This would then overwrite
a font resource if we had previously added it. Make sure that we
merge our new font resource into the annotation's resources instead.

## What's new

### Deprecations (DEP)
- Deprecate support for abbreviations in decode_stream_data (#3617) by @stefan6419846

### New Features (ENH)
- Add ability to add font resources for 14 Adobe Core fonts in text widget annotations (#3624) by @PJBrs

### Bug Fixes (BUG)
- Avoid invalid load for ICCBased FlateDecode images in mode 1 (#3619) by @stefan6419846

### Robustness (ROB)
- Fix AESV2 decryption when /Length missing in encrypt dict (#3629) by @dmitry-kostin
- Fix merging when annotations point to NullObject (#3613) by @stefan6419846
- Check for `self._info` being None in `compress_identical_objects` (#3612) by @stefan6419846

[Full Changelog](6.6.2...6.7.0)