v8.0: add translation to other languages; improve tree view UI; remove some minor settings

[8.0.0] - 2024-06-29

Added

1. Made it possible to translate JsonTools into other languages.
2. Made the tree view font size configurable with the tree_view_font_size setting. Fixes issue 66.
3. Added dark mode tree view icons (addresses this GH issue comment).
4. Allow users to manually enter directory names in the JSON from files and APIs form (referred to as "grepper form" for the rest of this section) rather than using a dialog or the dropdown menu.
5. Added a "Search directories" button to the grepper form.

Changed

1. Removed the max_threads_parsing setting for the grepper form, because the underlying implementation was changed in a way that made that setting useless.
2. Removed the allow_datetimes setting, because I do not feel confident that the potential benefits of the setting outweigh the danger of accidentally changing the format of people's dates or datetimes in some way that they were not expecting.
3. When all files have been parsed in the directory chosen with the grepper form, the directory name is no longer reset to the default value.
4. Added a hard limit to the total combined size of all files parsed by the grepper form, to avoid hitting memory errors.

Fixed

1. Avoid unnecessarily refreshing the styles of all forms when settings other than use_npp_styling or tree_view_font_size are changed.
2. The list of recently chosen directories in the grepper form is pre-filtered for existing directories, to hide the partial directory names that contaminate the config file.
3. Fix bug where, if a setting in the config file had an invalid value (for example, a numeric setting having a value of blah), there might be an uncaught exception that would cause Notepad++ to crash. This bug appeared to be most likely to occur when the localization is not set to en-us.