fix(ios/textview): switch order of _setNativeText and _refreshColor in showText-method

[felixkrautschuk]

fix(ios/textview): switch order of _setNativeText and _refreshColor in showText-method

The color should be refreshed after setting the text to keep the styles.

Fixes #8764

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• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
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• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/WritingUnitTests.md.

What is the current behavior?

What is the new behavior?

Fixes #8764 .

[NathanWalker]

Thank you @felixkrautschuk ! If possible and time permitting would be possible to add a sample case to the toolbox app that exemplified the behavior? That way we could try it both ways under some other conditions to ensure no side effects which may need an additional check of sorts.
❤️

[NathanWalker]

Actually that issue provides the repro thanks for that.

[felixkrautschuk]

@NathanWalker sorry, I had no time at the weekend to respond, but glad you've found my demo within the issue-thread and you've merged this.