refactor: remove alias json for support add custom language support

[yutingzhao1991]

check list

• Add test cases for the changes.
• Passed the CI test.

Description

use hljs.getLanguage for check language support, so I can add new language support with hexo plugin.

Additional information

for hexojs/hexo#5639

[coveralls]

coverage: 96.875%. remained the same
when pulling 8a82343 on yutingzhao1991:feat/includelangs
into 1ad96ca on hexojs:master.

[stevenjoezhang]

The highlight_alias.json file was introduced almost a decade ago, apparently to address efficiency issues with loading aliases in highlight.js: 7f6469e
If this issue no longer exists, using hljs.getLanguage would indeed be a better option.

[SukkaW]

What about still preferring the alias, but even if the existing alias doesn't match, then use the hljs.getLanguage as a fallback? This prevents unexpected behavior changes.

[yutingzhao1991]

What about still preferring the alias, but even if the existing alias doesn't match, then use the hljs.getLanguage as a fallback? This prevents unexpected behavior changes.

You are right, I already fix it.

btw: many useless commit, use squash merge.

[SukkaW]

LGTM now. What do you think? @hexojs/core

[yoshinorin]

@yutingzhao1991
Would you please fix lint errors? Other than that, LGTM.