Remove legacy electronic storage code + small e-storage fixes

[ShnitzelX2]

Summary

Infrastructure "remove legacy electronic storage code + small e-storage fixes"

Purpose of change

One of many planned follow-ups to #79097

Removes/modifies most code that was made obsolete by that PR.

• Fixes a small bug where reading external devices didn't check for compatibility
• Adds EBOOKSAVE to eink_tablet_pc
• Removes a test item group that I forgot

Describe the solution

Remove code, fix bug; this was part of #79097 but was left out to reduce size.

Part of reworking the legacy content was making e-files and software separate item categories.

Describe alternatives you've considered

Testing

Verified bug was fixed, ran clang-tidy and tests locally.

Additional context

More coming soon

[github-actions]

Spell checker encountered unrecognized words in the in-game text added in this pull request. See below for details.

Click to expand

• softwares

This alert is automatically generated. You can simply disregard if this is inaccurate, or (optionally) you can also add the new words to tools/spell_checker/dictionary.txt so they will not trigger an alert next time.

Hints for adding a new word to the dictionary

• If the word is normally in all lowercase, such as the noun word or the verb does, add it in its lower-case form; if the word is a proper noun, such as the surname George, add it in its initial-caps form; if the word is an acronym or has special letter case, such as the acronym CDDA or the unit mW, add it by preserving the case of all the letters. A word in the dictionary will also match its initial-caps form (if the word is in all lowercase) and all-uppercase form, so a word should be added to the dictionary in its normal letter case even if used in a different letter case in a sentence.
• For a word to be added to the dictionary, it should either be a real, properly-spelled modern American English word, a foreign loan word (including romanized foreign names), or a foreign or made-up word that is used consistently and commonly enough in the game. Intentional misspelling (including eye dialect) of a word should not be added unless it has become a common terminology in the game, because while someone may have a legitimate use for it, another person may spell it that way accidentally.

[ZhilkinSerg]

add_contained_ebooks should be obsoleted too in favor of add_contained_efiles

[GuardianDll]

(continued from above) ERROR : D:\a\Cataclysm-DDA\Cataclysm-DDA\src\item.cpp:1826 [put_in] tried to put an item (test_textbook_fabrication) count (1) in a container (test_ebook_reader) that cannot contain it: pocket with type (E_FILE_STORAGE) not found

[github-actions]

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