feat(Translate): Implement post-processing layout analysis to avoid content overlap and optimize visual appearance

[awwaawwa]

Currently, the Chinese line spacing is fixed at 1.4 times to avoid overlap. By implementing layout analysis, the line spacing can be appropriately increased, utilizing the current post-paragraph blank space to improve the visual appearance.

[timelic]

保持行距一致更好。稀疏行距在排版上是大忌。

我不反对对全文进行扫描之后用自适应的统一行距，但是不应该就每一段用不同的行距。

[awwaawwa]

My idea is to try to unify the line spacing as much as possible, and reduce the line spacing where it doesn't fit. For example, first calculate the maximum allowable line spacing page by page, then take the 90th percentile, and finally compress the remaining space. Consider using dynamic programming for calculating and reducing line spacing, as using greedy algorithms might yield poorer results. Of course, in the initial stage, a quick implementation using a greedy algorithm might be used to verify feasibility.

[timelic]

由于要将代码改写成page-independent来并行化，感觉这种统一分析很难做。并且，似乎也无法区分哪些文本属于“正文”，从而统一正文的行距。

[awwaawwa]

Maybe it can be done by word count, with the one having more words serving as the main text. Page independence is not a concern; it can be done in multiple stages, with as much parallel processing as possible within each stage, and serial processing between different stages.