Add release-draft workflow and Marketplace publish; refactor CI tests; bump version to 2.2.0

[wl2027]

Motivation

• Automate creation of GitHub Release drafts from gradle.properties version and attach built plugin artifacts.
• Separate publishing to JetBrains Marketplace into a dedicated workflow triggered on published releases.
• Improve CI by splitting and stabilizing test stages and avoiding flaky Plugin Verifier and configuration-cache issues.

Description

• Replaced single Build workflow with a multi-job pipeline in .github/workflows/build.yml that detects crate version (detect_version), runs tests (test), builds the plugin distribution (release), and creates or updates a draft release with artifacts and changelog.
• Added publish-marketplace.yml to publish the plugin to JetBrains Marketplace when a release is published and validated against gradle.properties version.
• Simplified and modernized UI test runner in run-ui-tests.yml to a matrix job that runs ./gradlew ideaUiTest across platforms and uploads UI test reports on failure.
• Updated test task wiring in build.gradle.kts to register unitTest, integrationTest, and ideaUiTest, added notCompatibleWithConfigurationCache(...) to avoid configuration-cache serialization issues for IntelliJ test setup, and wired check to depend on these tasks.
• Removed the Plugin Verifier step and the old runIdeForUiTests helper, and added safer Gradle invocation flags in CI (--no-configuration-cache, --console=plain, --continue where appropriate).
• Bumped project version in gradle.properties from 2.1.0 to 2.2.0 and updated CHANGELOG.md with 2.2.0 notes describing the new release flow and CI changes.

Testing

• No CI runs were executed as part of this PR; the workflows were added/updated so GitHub Actions will run them on the next push/release.
• The CI is now configured to run unitTest, integrationTest, and ideaUiTest via Gradle in the test job and to run ideaUiTest in the UI matrix workflow.
• Test reports are uploaded as artifacts on failure using actions/upload-artifact@v7 (configured per-job reporting behavior).

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Allow existing drafts to be refreshed

When another commit is pushed while the version remains unchanged, the draft created by the first run makes gh release view "$version" succeed, so this run sets is_new_version=false and skips the release job. The existing draft therefore retains the distribution and target SHA from the earlier commit, even though lines 152–160 explicitly attempt to support updating an existing release. The GitHub CLI documentation confirms that gh release view returns release metadata including isDraft; distinguish published releases/tags from drafts so subsequent successful pushes can rebuild and replace the draft assets.

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