fix: 3d line bounding box

[FishOrBear]

        let dxf = new DxfWriter;
        dxf.addLine(point3d(0, 0, 0), point3d(0, 0, 100));

This bug causes the DXF of 3D straight lines to fail to open in ACAD.

I don't think this implementation should be provided. src\DxfDocument.ts:

should be calculated by developers themselves. Now in the source code, the Box of many entities is wrong. If we didn't write we wouldn't get this error instead.

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (08cf5f5) 93.54% compared to head (bcd3d4b) 93.55%.

:exclamation: Current head bcd3d4b differs from pull request most recent head 2960346. Consider uploading reports for the commit 2960346 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #77 +/- ## ======================================= Coverage 93.54% 93.55% ======================================= Files 74 74 Lines 7658 7660 +2 Branches 527 529 +2 ======================================= + Hits 7164 7166 +2 Misses 494 494 ``` | [Impacted Files](https://codecov.io/gh/dxfjs/writer/pull/77?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs) | Coverage Δ | | |---|---|---| | [src/Internals/BoundingBox.ts](https://codecov.io/gh/dxfjs/writer/pull/77?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs#diff-c3JjL0ludGVybmFscy9Cb3VuZGluZ0JveC50cw==) | `100.00% <100.00%> (ø)` | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs)

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