feat(oss): include thrift/lib/(cpp,cpp2,java,py,python) from fbthrift

Summary:
Map `fbcode/thrift/lib/cpp` into sapling so it is available to satisfy the error shown below. (As well as `cpp2`, `java`, `py` and `python`.)

This may not be the correct mapping (fbthrift uses a copy in `xplat/thrift`), but it is necessary to unblock OSS buck development as fbthrift does prune all `BUCK` files from its OSS repo.

The error in the OSS buck build:
```
$ buck2 build //eden/fs/service:edenfs-oss

...

Error running analysis for `gh_facebook_sapling//eden/fs/service:edenfs-oss (prelude//platforms:default#2c621926a02f7469)`

Caused by:
    0: Error in configured node dependency, dependency chain follows (-> indicates depends on, ^ indicates same configuration as previous):
              gh_facebook_sapling//eden/fs/service:edenfs-oss (prelude//platforms:default#2c621926a02f7469)
           -> gh_facebook_sapling//eden/fs/service:server (^)
           -> gh_facebook_sapling//thrift/lib/cpp:event_handler_base (^)

    1: looking up unconfigured target node `gh_facebook_sapling//thrift/lib/cpp:event_handler_base`
    2: Error loading targets in package `gh_facebook_sapling//thrift/lib/cpp` for target `gh_facebook_sapling//thrift/lib/cpp:event_handler_base`
    3: package `gh_facebook_sapling//thrift/lib/cpp:` does not exist
           missing `BUCK` file (also missing alternatives `BUCK.v2`, `BUCK`)
```

X-link: facebook/sapling#1138

Reviewed By: muirdm

Differential Revision: D83259168

Pulled By: quark-zju

fbshipit-source-id: 52cbe1a73b74580e33d98c8defc438c831d723c3

Author: ben--

build/fbcode_builder/manifests/eden

@@ -63,6 +63,11 @@ sapling
 # for internal builds that use getdeps
 fbcode/fb303 = fb303
 fbcode/common/rust/shed = common/rust/shed
+fbcode/thrift/lib/cpp = thrift/lib/cpp
+fbcode/thrift/lib/cpp2 = thrift/lib/cpp2
+fbcode/thrift/lib/java = thrift/lib/java
+fbcode/thrift/lib/py = thrift/lib/py
+fbcode/thrift/lib/python = thrift/lib/python
 fbcode/thrift/lib/rust = thrift/lib/rust
 
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