Implemented ternary conditional expression

[ByteWolf-dev]

What type of change does this PR perform?

• [ ] Maintenance (Non-breaking change that updates dependencies)
• [ ] Info or documentation change (Non-breaking change that updates repo info files (e.g. README.md, CONTRIBUTING.md, etc.) or online documentation)
• [ ] Website feature update or docs development changes (Change that changes the design or functionality of the websites or docs)
• [ ] Development or internal changes (These changes do not add new features or fix bugs, but update the code in other ways)
• [ ] Bug fix (Non-breaking change which fixes an issue)
• [x] New feature (Non-breaking change which adds functionality)
• [ ] Breaking change (Major bug fix or feature that would cause existing functionality not to work as expected.)
• [ ] Requires a documentation update, as it changes language or compiler behaviour

Summary

Implemented ternary conditional expression.

Closes #534

Detailed Changelog

Added

• Implemented Conditional Expression (COND ? EXP : EXP) as a ternary operator (#534)
• New function KipperTypeChecker.validConditionalExpression(), which ensures that a conditional expression is valid.

Does this PR create new warnings?

None.

Linked issues or PRs

• [x] #534

[github-actions[bot]]

size-limit report 📦

Path	Size	Loading time (3g)	Running time (snapdragon)	Total time
./kipper/web/kipper-standalone.min.js	137.36 KB (0%)	2.8 s (0%)	470 ms (+31.55% 🔺)	3.3 s
./kipper/web/kipper-standalone.js	137.4 KB (0%)	2.8 s (0%)	492 ms (+37.08% 🔺)	3.3 s

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 88.88889% with 2 lines in your changes missing coverage. Please review.

Project coverage is 83.22%. Comparing base (8869ef0) to head (0a0fcdb).

Files	Patch %	Lines
...ore/src/compiler/analysis/analyser/type-checker.ts	66.66%	1 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev-next #565 +/- ## ============================================ + Coverage 83.16% 83.22% +0.06% ============================================ Files 207 207 Lines 3653 3667 +14 Branches 416 418 +2 ============================================ + Hits 3038 3052 +14 + Misses 440 439 -1 - Partials 175 176 +1 ```

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