Replace some Japanese terms

[Kuhaku9893]

#1119

• Replaced direct translations with terms already widely used within Japan's RTA community
• Adjusted parts that felt unnatural in direct translations to sound more natural
• Filled in missing text that had been omitted from longer descriptions, such as component description

[CryZe]

Here's some general feedback from Copilot, idk how much of this makes sense:

• “自己ベスト” vs “ベストタイム”: Rust consistently uses “自己ベスト” for PB, while TS uses “ベストタイム” in the save prompt. Compare japanese.ts:72-73 with japanese.rs:515-516.
• “得失タイム” vs “短縮/ロスタイム”: Rust labels gained/lost time as “得失タイム”, while TS uses “短縮/ロスタイム” for the column label. Compare japanese.rs:225 with japanese.ts:277-278.
• “リード/遅れ” vs “リード/遅れタイム”: Rust typically uses “リード/遅れ” without “タイム”, while TS has the column label “リード/遅れタイム”. Compare japanese.rs:29 with japanese.ts:274-275.

[Kuhaku9893]

As a term encompassing not only personal best but also segment bests, japanese.ts:72-73 uses ベストタイム.

得失タイム and 短縮/ロスタイム are interpreted as having the same meaning; the difference in the highlighted section stems from retaining the original translation's phrasing.
I believe it's sufficient as long as it's consistent within a single component, so I think it's fine as is.

The presence or absence of タイム follows the original translation.
In japanese.rs:29, it appears within a sentence. Given the context of a timer app, it can be correctly interpreted even without タイム and remains natural in Japanese.
In japanese.ts:274-275, this word is used alone. While it can still be correctly interpreted without タイム, I feel that including タイム makes it more appropriate as the name of a selection option.

[CryZe]

Alright, CI should pass in a few minutes and then it should auto merge and publish. Thank you so much for the time and effort that you put into this, I really appreciate it.