Apply textContent on flush

[Juice10]

When scrubbing through replays I bumped into the issue that textContent doesn't always get applied on stylesheets.
This PR fixes that issue and adds tests for a number of edge cases

[YunFeng0817]

This is a great fix and could you please also see whether #853 solves this problem or not?

[Juice10]

This is a great fix and could you please also see whether #853 solves this problem or not?

@Mark-Fenng #853 solves the "should apply fast-forwarded StyleSheetRules that came after stylesheet textContent overwrite" test case, but doesn't solve the "should overwrite all StyleSheetRules by replacing style element's textContent while fast-forwarding" test case that was added in this PR.

Test results:

 replayer › should overwrite all StyleSheetRules by replacing style element's textContent while fast-forwarding

    expect(received).toEqual(expected) // deep equality

    Expected: false
    Received: true

      327 |     `);
      328 |
    > 329 |     expect(result).toEqual(false);
          |                    ^
      330 |   });
      331 |
      332 |   it('should apply fast-forwarded StyleSheetRules that came after stylesheet textContent overwrite', async () => {

      at test/replayer.test.ts:329:20
      at step (test/replayer.test.ts:34:23)
      at Object.next (test/replayer.test.ts:15:53)
      at fulfilled (test/replayer.test.ts:6:58)

[Karliz24]

Excelente