Add spring-integration-grpc when Spring Integration and gRPC starters are selected

[cppwfs]

Currently, Spring Initializr has a feature where selecting Spring Integration alongside other protocol-specific starters (for example Apache Kafka) automatically adds the corresponding Spring Integration module to the generated build file (spring-integration-kafka).

Spring integration now has gRPC inbound and outbound gateways, so similar support for gRPC dependencies can be added.

So when a user selects both Spring Integration and a Spring gRPC starter(both client and server), the Initializr should automatically add the spring-integration-grpc dependency to the generated project.

The dependencies should look like:

dependencies {
	implementation 'org.springframework.boot:spring-boot-starter-integration'
	implementation 'org.springframework.boot:spring-boot-starter-grpc-client'
	implementation 'org.springframework.integration:spring-integration-grpc'

	//Test
	testImplementation "org.springframework.boot:spring-boot-starter-grpc-test"
}

-or

dependencies {
	implementation 'org.springframework.boot:spring-boot-starter-integration'
	implementation 'org.springframework.boot:spring-boot-starter-grpc-server'
	implementation 'org.springframework.integration:spring-integration-grpc'

	//Test
	testImplementation "org.springframework.boot:spring-boot-starter-grpc-test"
}

The original idea was mentioned here: spring-projects/spring-integration-samples#382 (comment)
by @artembilan

[mhalbritter]

We should only do this for Boot 4.1+, as the spring-grpc-dependency has been added in Spring Integration 7.1.0-M1.

[mhalbritter]

Currently blocked on #2127.