PBJ does not handle package directive correctly

[jsync-swirlds]

PBJ does not handle the package directive correctly when another message refers to a message defined in a file with a package directive.
The package directive, in protoc, is treated as a C++ namespace, rather than a Java package, and common prefixes are elided when matching between the current file and a search space. The PBJ compiler, however, treats it as a Java package and requires a full-text match. This causes MANY third-party proto files (some of which we may wish to use, such as validation plugins) to fail compilation for PBJ.

Example

parent_item.proto file:

syntax = "proto3"

package one.package.name;

import "children/child_item.proto";

message Item {
  repeated child.ChildItem children = 1;
}

children/child_item.proto

syntax = "proto3"

package one.package.name.child;

message ChildItem {
  uint32 a_value = 1;
}

The canonical protoc compiler handles these correctly and compiles as expected.
PBJ fails with an error message similar to this:

Not found pbj package for message or enum [child.ChildItem] in file [test-protobufs/one/package/name/parent_item.proto]