chore: update development configs, formatting tools, and CI enhancements (#4130)

# Description of Changes

- **What was changed**  
- Bumped `java.format.settings.google.version` to **1.28.0** in
`.devcontainer/devcontainer.json` and `.vscode/settings.json`.
- Expanded ignore patterns in `.devcontainer/devcontainer.json` to cover
`app/core/`, `app/common/`, `app/proprietary/` directories.
- Added a new top‐level `.dockerignore` to exclude build artifacts,
virtual environments, logs, OS files, and markdown docs.
- Consolidated EditorConfig YAML globs into `*.{yml,yaml}` to remove
duplication.
- Fixed missing newline in `.github/config/.files.yaml` and added label
metadata (`from_name`/`description`) in `.github/labels.yml`.
  - Updated `build.gradle`:
- Introduced `junitPlatformVersion = "1.12.2"` and replaced hard-coded
launcher versions.
- Applied the `jacoco` plugin across all subprojects and configured
`jacocoTestReport` (XML + HTML).
    - Wire-up `jacocoTestReport` to run after tests.  
- **Why the change was made**  
- Ensure all formatting tools (Google Java Format) stay in sync across
editors and containers.
- Clean up ignore rules to prevent build artifacts and sensitive files
from creeping into images and repos.
- Improve CI visibility by generating code-coverage reports with JaCoCo.
- Keep GitHub configuration files well-formed and enrich label
definitions for automation.

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

.devcontainer/devcontainer.json

@@ -49,7 +49,7 @@
                 "java.configuration.updateBuildConfiguration": "interactive",
                 "java.format.enabled": true,
                 "java.format.settings.profile": "GoogleStyle",
-                "java.format.settings.google.version": "1.26.0",
+                "java.format.settings.google.version": "1.28.0",
                 "java.format.settings.google.extra": "--aosp --skip-sorting-imports --skip-javadoc-formatting",
                 "java.saveActions.cleanup": true,
                 "java.cleanup.actions": [
@@ -79,9 +79,17 @@
                     ".venv*/",
                     ".vscode/",
                     "bin/",
+                    "app/core/bin/",
+                    "app/common/bin/",
+                    "app/proprietary/bin/",
                     "build/",
+                    "app/core/build/",
+                    "app/common/build/",
+                    "app/proprietary/build/",
                     "configs/",
+                    "app/core/configs/",
                     "customFiles/",
+                    "app/core/customFiles/",
                     "docs/",
                     "exampleYmlFiles",
                     "gradle/",
@@ -93,6 +101,9 @@
                     ".git-blame-ignore-revs",
                     ".gitattributes",
                     ".gitignore",
+                    "app/core/.gitignore",
+                    "app/common/.gitignore",
+                    "app/proprietary/.gitignore",
                     ".pre-commit-config.yaml"
                 ],
                 "java.signatureHelp.enabled": true,