[HUDI-3195] optimize spark3 pom and modify build command

[YannByron]

with Spark3.0:
-- mvn clean install -DskipTests=true -P "scala-2.12,spark3.0.x"

with Spark3.1:
-- mvn clean install -DskipTests=true -P "scala-2.12,spark3.1.x"

with Spark3.2
-- mvn clean install -DskipTests=true -P "scala-2.12,spark3"

[YannByron]

@leesf @xushiyan please review this with high priority.

[xushiyan]

LGTM. Can you update the README as well? Also please remember need a separate PR for 0.10.1 where we don't have spark 3.2 support

[hudi-bot]

CI report:

• 82d1e2a Azure: SUCCESS

Bot commands

@hudi-bot supports the following commands:

• @hudi-bot run azure re-run the last Azure build

[YannByron]

LGTM. Can you update the README as well? Also please remember need a separate PR for 0.10.1 where we don't have spark 3.2 support

If you don't patch #4488 and this to 0.10.1, the previous commands for spark3.0.x and spark3.1.x works.

# Build against Spark 3.2.0 (default build shipped with the public jars)
mvn clean package -DskipTests -Dspark3

# Build against Spark 3.1.2
mvn clean package -DskipTests -Dspark3.1.x

# Build against Spark 3.0.3
mvn clean package -DskipTests -Dspark3.0.x

README is OK, not need to be changed.