Support WebM seeking operation

[John-Gdi]

Support webm video seeking operation with minimal modification. Currently, it only support 3.x version since master 4.0 version has abandoned webm format support.

Modified files:
1.modules/webm/video_stream_webm.cpp
2.thirdparty/libsimplewebm/WebMDemuxer.cpp
3.thirdparty/libsimplewebm/WebMDemuxer.hpp

Kapture.2022-02-06.at.11.49.43.mp4

[fire]

There's a whitespace formatting change that needs to be applied.

[John-Gdi]

There's a whitespace formatting change that needs to be applied.

Thanks, and i have modified the formatting change

[akien-mga]

There will be more style issues to fix, see https://docs.godotengine.org/en/stable/community/contributing/code_style_guidelines.html

But this PR should be reopened against the 3.x branch, that's where feature development for 3.5 is done.

[John-Gdi]

There will be more style issues to fix, see https://docs.godotengine.org/en/stable/community/contributing/code_style_guidelines.html

But this PR should be reopened against the 3.x branch, that's where feature development for 3.5 is done.

Thanks for your guidance, and i correct the issue according to the guidelines, as well as the suggestion from @Calinou , before the third commit, i have use pre-commit to ensure that "Files in this commit comply with the clang-format rules."

When this PR is Ready, i will reopen it on 3.x branch, and open PR on 3.x first next time, Thanks.

[fire]

I have asked @kidrigger to review and am testing too.

[akien-mga]

Superseded by #57744.