Use spring mvc rest to replace the original netty http rest Created a new package `org/apache/doris/httpv2`, and the origin implementations under `org/apache/doris/http` remain unchanged. This part of the code will not be used at present, so it will not affect existing functions. API document can be found in #4584 Proposal #4308
# fe-common This module is used to store some common classes of other modules. # spark-dpp This module is Spark DPP program, used for Spark Load function. Depends: fe-common # fe-core This module is the main process module of FE. Depends: fe-common, spark-dpp