Fixed `VARIABLE_NAME_INCORRECT_FORMAT` false positive when a property has a backing field

[diphtongue]

What's done:

• fixed warning VARIABLE_NAME_INCORRECT_FORMAT on backing field.
• added warning test.

Closes #1711

[nulls]

Does it close #1709 as well?

[github-actions[bot]]

JUnit Tests (macOS, EnricoMi/publish-unit-test-result-action@v2)

   164 files   - 1     164 suites   - 1   8m 49s :stopwatch: + 1m 36s 1 397 tests +2  1 361 :heavy_check_mark: +2  36 :zzz: ±0  0 :x: ±0  2 776 runs  +2  2 740 :heavy_check_mark: +2  36 :zzz: ±0  0 :x: ±0 

Results for commit d84c98c2. ± Comparison against base commit 81a74293.

This pull request removes 2 and adds 4 tests. Note that renamed tests count towards both.

``` com.saveourtool.diktat.plugin.gradle.DiktatGradlePluginTest ‑ check default reporter type value() com.saveourtool.diktat.plugin.gradle.ReporterSelectionTest ‑ should fallback to plain reporter for unknown reporter types() ``` ``` com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should not trigger on backing field() com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should trigger on backing field with no matching property() com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should trigger on backing field with setter() com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should trigger on backing field with unmatched type() ```

:recycle: This comment has been updated with latest results.

[github-actions[bot]]

JUnit Tests (Windows, EnricoMi/publish-unit-test-result-action@v2)

   164 files   - 1     164 suites   - 1   6m 44s :stopwatch: -13s 1 397 tests +2  1 380 :heavy_check_mark: +2  17 :zzz: ±0  0 :x: ±0  2 776 runs  +2  2 759 :heavy_check_mark: +2  17 :zzz: ±0  0 :x: ±0 

Results for commit d84c98c2. ± Comparison against base commit 81a74293.

This pull request removes 2 and adds 4 tests. Note that renamed tests count towards both.

``` com.saveourtool.diktat.plugin.gradle.DiktatGradlePluginTest ‑ check default reporter type value() com.saveourtool.diktat.plugin.gradle.ReporterSelectionTest ‑ should fallback to plain reporter for unknown reporter types() ``` ``` com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should not trigger on backing field() com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should trigger on backing field with no matching property() com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should trigger on backing field with setter() com.saveourtool.diktat.ruleset.chapter1.IdentifierNamingWarnTest ‑ should trigger on backing field with unmatched type() ```

:recycle: This comment has been updated with latest results.

[codecov[bot]]

Codecov Report

Attention: 8 lines in your changes are missing coverage. Please review.

Comparison is base (51195ee) 78.77% compared to head (f9799af) 78.72%.

Files	Patch %	Lines
.../diktat/ruleset/rules/chapter1/IdentifierNaming.kt	57.89%	0 Missing and 8 partials :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1810 +/- ## ============================================ - Coverage 78.77% 78.72% -0.05% - Complexity 2430 2441 +11 ============================================ Files 126 126 Lines 8526 8544 +18 Branches 2150 2163 +13 ============================================ + Hits 6716 6726 +10 Misses 850 850 - Partials 960 968 +8 ```

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[diphtongue]

Does it close #1709 as well?

No