Deferred translation class with optional context for option/effect/item-action names

[Qrox]

Summary

SUMMARY: I18N "Deferred translation class with optional context for option/effect/item-action names"

Purpose of change

There are several places in both cpp and json code where a word with multiple meanings is used without translation context. This makes it hard to translate the given strings in some other languages. This PR adds the ability to specify a translation context in these cases.

Closes #21760.

Describe the solution

1. A translation class is created which supports an optional translation context and deserialization from JSON;
2. Code for options, effects, and item actions is adjusted to use the new translation class, and JSON strings that needed a context are updated to include one.
3. Keywords for the xgettext call in update_pot.sh is updated so it also searches for the constructor of the translation class;
4. The python scripts used for extracting json strings are updated so they work properly on Windows;
5. The python scripts are updated to extract json strings with context;
6. merge_po.sh is updated to disable fuzzy matching and remove obsolete strings; (I'm not sure about this one. The .po files in the repo does not have fuzzy matching nor obsolete strings, but maybe they are not removed in the script for a reason? @BrettDong should merge_po.sh be kept as is?)
7. Updated documentations to reflect the new translation class and JSON syntax;
8. Also fixed excess spaces in language names.

Additional context

I need comments on the changes to the shell and python scripts, as I'm not very familiar with the languages.

The following are some screenshots showing the changes with this PR. I've marked relevant text with English so it's easier to see what is changed.

Before:

Item action menu:

The translations for "play - handheld game machine" and "smoke - cigar" do not make sense here.

Options menu:

According to the translation, the option is "physically disabled".

Character info UI:

These translations are correct.

After (after generating, editing, and compiling .po files):

Item action menu:

Options menu:

Character info UI:

[BevapDin]

It would be better to call jsarr.throw_error to generate an exception along with a proper JSON context.

[BevapDin]

Don't include "json.h" here, it's quite large and has more dependencies. You don't need to derive from JsonDeserializer, having a deserialze function with proper signature is enough.

[BevapDin]

Have you considered to adding a translation::operator std::string() const { return translated(); } function? This would implicitly convert translation objects to std::string (applying the translation).

This means you don't need to add translated() explicitly so often.

[AMurkin]

Will close #24102?

[Qrox]

@AMurkin Currently keybindings are not using the translation class, but that's definitely doable. On another hand this should close #21760 you referenced in that issue.

[BrettDong]

merge_po.sh is a pre-Transifex era thing. The script is actually not used anymore.

[Qrox]

@BrettDong I'll adapt the script as a tool for locally testing translations then.

[Qrox]

Have you considered to adding a translation::operator std::string() const { return translated(); } function?

I'm not sure about it. It could of course make the code less verbose, but I'm concerned that if someone wants to use the class in more places, and happens to forget to change the variable from std::string to translation, then the string may get translated prematurely. I guess it's better to keep it explicit.

[Qrox]

@AMurkin Actually the strings you mentioned in #24102 are fixable by simply using pgettext, so I'm not going to address it in this PR.

[jbytheway]

I see you've changed the Python scripts to use some Python 3-isms, rather than Python 2.

This is not really about this PR, but the #!/usr/bin/env python lines should really be changed to specify either python2 or python3 specifically, because just python can end up using either one and makes it difficult to have the script work everywhere (which leads to things like you having to make these changes).

[Qrox]

Thanks, I'll change them to python3 since extract_json_strings.py already uses python3.