This is a major change that has some fallout in many packages in this module.
- Most of the changes are to canonicalize imports to use the packages in google.golang.org/protobuf/types
- The desc/protoprint package now has custom logic to print message literals for custom options. This allows
   it to respect line-breaking options on the printer.
- The desc package, and all of the descriptor implementations, now wrap implementations of protoreflect.Descriptor in the protobuf API v2 runtime. This does add some overhead since converting from descriptor protos now must undergo two conversions: one to protoreflect.Descriptor and then another to wrap that with a desc.Descriptor. But the benefit is now much better interop with the API v2 protoreflect functionality. It is now easy to convert between the two representations.
- The desc/protoparse package is heavily overhauled. Most of the implementation code has been removed. It is now an API shim to provide the same API as before, but to use github.com/bufbuild/protocompile under the hood for the actual parsing/compiling. That package has a different AST representation, so using the ParseToAST entry point now has extra overhead to convert the protocompile AST to this module's AST types.

Since this is such a huge change, I will be creating a release candidate first, and hoping users can put that to work and report any bugs/breakages before I make an official release.

)

thanks to underlying protoreflect.Descriptor impl being used to construct descriptors

…code info (#550)

Bumps [golang.org/x/text](https://github.com/golang/text) from 0.3.2 to 0.3.8.
- [Release notes](https://github.com/golang/text/releases)
- [Commits](golang/text@v0.3.2...v0.3.8)

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [golang.org/x/net](https://github.com/golang/net) from 0.0.0-20200625001655-4c5254603344 to 0.7.0.
- [Release notes](https://github.com/golang/net/releases)
- [Commits](https://github.com/golang/net/commits/v0.7.0)

Signed-off-by: dependabot[bot] <support@github.com>

* update protocompile to latest, to resolve data races
* also updates to latest (v22.0) version descriptor.proto
* should resolve regression in protoparse related to returning dynamic extension values

…possible init crash (#555)

…buf API

…amine dependencies

…ity issues (#567)