Add ability to pass predefined result

[vjik]

Q	A
Is bugfix?	❌
New feature?	✔️
Breaks BC?	❌
Fixed issues	#598

[what-the-diff[bot]]

PR Summary

• Added method to check if ValidationContext is initialized A new method called isInitialized() has been added to the ValidationContext.

• Improved validation context initialization logic in Validator::validate() The validation context now allows passing a predefined result into the validator, which can be used for further rules processing if there are no errors. This enables the creation of custom rules that can act as wrappers around other rules.

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.03 :tada:

Comparison is base (b0044e0) 94.79% compared to head (3eb633c) 94.83%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #599 +/- ## ============================================ + Coverage 94.79% 94.83% +0.03% - Complexity 735 739 +4 ============================================ Files 86 86 Lines 2229 2244 +15 ============================================ + Hits 2113 2128 +15 Misses 116 116 ``` | [Impacted Files](https://codecov.io/gh/yiisoft/validator/pull/599?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=yiisoft) | Coverage Δ | | |---|---|---| | [src/ValidationContext.php](https://codecov.io/gh/yiisoft/validator/pull/599?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=yiisoft#diff-c3JjL1ZhbGlkYXRpb25Db250ZXh0LnBocA==) | `100.00% <100.00%> (ø)` | | | [src/Validator.php](https://codecov.io/gh/yiisoft/validator/pull/599?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=yiisoft#diff-c3JjL1ZhbGlkYXRvci5waHA=) | `100.00% <100.00%> (ø)` | | 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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[vjik]

See https://github.com/yiisoft/validator/issues/598#issuecomment-1497276408