Simplify category sources config

[rustamwin]

Q	A
Is bugfix?	❌
New feature?	✔️/❌
Breaks BC?	✔️/❌
Fixed issues	Support upcoming release of yiisoft/definitions

[what-the-diff[bot]]

• The translator.app category source was removed from the config/common.php file
• A new translation service definition with a tag 'translation.categorySource' was added to the config/common.php file 3a) In params, we have an array of references for all categories that should be used by TranslatorInterface::class (the default one is app). This array has been replaced by a single reference: Reference::to('tag@translation.categorySource') in common configuration file and it's now empty in params configuration files; 3b) We can add more than one category sources using this approach - just add another entry into services definitions section with appropriate tags like "translations" or whatever you want and then use them as many times as needed via addCategorySources() method call on TranslatorInterface class instance;

[codecov[bot]]

Codecov Report

Base: 94.75% // Head: 95.23% // Increases project coverage by +0.48% :tada:

Coverage data is based on head (21737eb) compared to base (8716af3). Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #90 +/- ## ============================================ + Coverage 94.75% 95.23% +0.48% + Complexity 104 103 -1 ============================================ Files 11 12 +1 Lines 267 273 +6 ============================================ + Hits 253 260 +7 + Misses 14 13 -1 ``` | [Impacted Files](https://codecov.io/gh/yiisoft/translator/pull/90?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=yiisoft) | Coverage Δ | | |---|---|---| | [config/common.php](https://codecov.io/gh/yiisoft/translator/pull/90/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=yiisoft#diff-Y29uZmlnL2NvbW1vbi5waHA=) | `100.00% <100.00%> (ø)` | | | [src/Translator.php](https://codecov.io/gh/yiisoft/translator/pull/90/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=yiisoft#diff-c3JjL1RyYW5zbGF0b3IucGhw) | `92.59% <100.00%> (-0.14%)` | :arrow_down: | | [src/SimpleMessageFormatter.php](https://codecov.io/gh/yiisoft/translator/pull/90/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=yiisoft#diff-c3JjL1NpbXBsZU1lc3NhZ2VGb3JtYXR0ZXIucGhw) | `97.61% <0.00%> (+2.38%)` | :arrow_up: | 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=yiisoft). 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=yiisoft)

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[rustamwin]

Need test

Added