Modularized Keychain Access

[overheadhunter]

This is the first step towards a more modular project in regards of integrations with third party services.

Instead of directly adding implementations to this project, we will rather use an interface defined in integrations-api, which can get implemented by various libs (including third party ones).

Those implementations can then be loaded using a ServiceLoader, which will yield 0..n objects (depending on the available libs during runtime):

cryptomator/main/commons/src/main/java/org/cryptomator/common/keychain/KeychainModule.java

Lines 18 to 31 in b382e43

	@Provides
	@Singleton
	static Set<ServiceLoader.Provider<KeychainAccessProvider>> provideAvailableKeychainAccessProviderFactories() {
	return ServiceLoader.load(KeychainAccessProvider.class).stream().collect(Collectors.toUnmodifiableSet());
	}
	@Provides
	@Singleton
	static Set<KeychainAccessProvider> provideSupportedKeychainAccessProviders(Set<ServiceLoader.Provider<KeychainAccessProvider>> availableFactories) {
	return availableFactories.stream() //
	.map(ServiceLoader.Provider::get) //
	.filter(KeychainAccessProvider::isSupported) //
	.collect(Collectors.toUnmodifiableSet());
	}

This PR removes the keychain maven module and adds integrations-api as a compile-time dependency. Libraries implementing integrations-api will only be present at runtime (to be included with the installers, if applicable).

Furthermore this PR removes system-specific dependencies. These should be part of system-specific service implementations (and as such transitive dependencies will be re-added when packaging installers).

[overheadhunter]

@swiesend @purejava I think you should be aware of this change:

To get rid of the reflection involved constructing the Linux keychain objects while not running into errors on macOS/Windows with the jars being unavailable, we've externalized such platform-specific code.

So if you want to update the Linux keychain integrations, head over to the integrations-linux repo.

[purejava]

Yes, thanks for the hint.

[swiesend]

Sounds like a proper engineering idea. Thanks for the update.