This commit refactors the Dokka documentation generation setup by centralizing its configuration into a new `DokkaConventionPlugin`.

Key changes include:
- Removing the fragmented Dokka configuration from the root `build.gradle.kts` file.
- Creating a `DokkaConventionPlugin` to apply a standardized Dokka setup across all modules.
- Applying the new convention plugin to Android application, Android library, and KMP library modules.
- Removing outdated Dokka V2 properties from `gradle.properties`.
- Updating dependency declarations for the Dokka plugin.

Signed-off-by: James Rich <2199651+jamesarich@users.noreply.github.com>

This commit refactors the build logic by creating dedicated convention plugins for Kover (code coverage) and Dokka (documentation).

Key changes:
- Created `KoverConventionPlugin` to apply and configure Kover for each module.
- Moved Dokka configuration logic from `DokkaConventionPlugin` into a reusable `configureDokka` function.
- Removed duplicated Kover and Dokka plugin applications and configurations from individual module `build.gradle.kts` files.
- Centralized Kover and Dokka aggregation logic in the `RootConventionPlugin`.
- Updated Android and KMP convention plugins to apply the new `meshtastic.kover` and `meshtastic.dokka` plugins.
- Updated copyright years across various build files.

This centralization simplifies module build scripts, reduces redundancy, and makes the build configuration more maintainable.

Signed-off-by: James Rich <2199651+jamesarich@users.noreply.github.com>