Add Dictionary Encoded vectors to PyVelox (#3859)

Summary:
This PR adds support for dictionary vectors in PyVelox. Currently base vectors are supported only for primitive (physical) types , and this also thus extends to Dictionary vectors.
Dictionary vectors are required for additional fuzzer support, and expression eval in pyvelox.

X-link: facebookincubator/velox#3859

Reviewed By: pedroerp

Differential Revision: D45409925

Pulled By: kgpai

fbshipit-source-id: 6b05a0d543332fea48d912f93f267896d005f4e2

build/fbcode_builder/getdeps/dyndeps.py

@@ -15,9 +15,6 @@
 from struct import unpack
 from typing import List, Optional
 
-from .envfuncs import path_search
-
-
 OBJECT_SUBDIRS = ("bin", "lib", "lib64")