refactor: decouple language layout assumptions from GeneralKeyboardIME (Part 5/6) (#426)

[prince-0408]

Description

This PR is Part 5 of 6 in modularizing GeneralKeyboardIME for #426.

It removes hardcoded language name checks ("English", "Russian", "Swedish", "German") for layout configurations (like conjugate view grid size and plural capitalization) from GeneralKeyboardIME.kt and decouples them into overridable configuration properties in language subclasses.

Detailed Changes Table:

File / Component	Changes Applied	Detailed Impact
GeneralKeyboardIME.kt	Introduced open configuration properties (defaultConjugateModeType: String = "3x2", defaultConjugateLayoutXML: Int = R.xml.conjugate_view_3x2, isPluralCapitalized: Boolean = false) and removed all hardcoded language name checks.	Completely decouples layout rules from the base class.
EnglishKeyboardIME.kt	Overrode defaultConjugateModeType = "2x2" and defaultConjugateLayoutXML = R.xml.conjugate_view_2x2.	Declares 2x2 layout explicitly in English IME subclass.
RussianKeyboardIME.kt	Overrode defaultConjugateModeType = "2x2" and defaultConjugateLayoutXML = R.xml.conjugate_view_2x2.	Declares 2x2 layout explicitly in Russian IME subclass.
SwedishKeyboardIME.kt	Overrode defaultConjugateModeType = "2x2" and defaultConjugateLayoutXML = R.xml.conjugate_view_2x2.	Declares 2x2 layout explicitly in Swedish IME subclass.
GermanKeyboardIME.kt	Overrode isPluralCapitalized = true.	Declares plural capitalization behavior explicitly in German IME subclass.

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Key Benefits:

• Decoupled Architecture: GeneralKeyboardIME contains zero hardcoded assumptions or when (language) checks for layout configurations.
• Extensibility: Adding future language keyboards requires zero modifications to GeneralKeyboardIME.kt.
• Zero Behavioral / API Breakage: Preserves exact layout rendering and plural capitalization across all languages.

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Related Issue

Refactors part of #426

[andrewtavis]

praise: Changes are great, @prince-0408! Thanks so much for your support here and the dedication to all of these refactors! 😊