refactor: make some wallet dependencies optional

requirements.txt

@@ -1,28 +1,23 @@
 bech32==1.2.0
 bitstring==3.1.6
+brotli==1.0.7
 cerberus==1.3.2
 certifi==2020.4.5.1
 chardet==3.0.4
-click==7.1.1
+click==7.1.2
 flask-assets==2.0
-flask-compress==1.4.0
+flask-compress==1.5.0
 flask-talisman==0.7.0
 flask==1.1.2
-gevent==20.4.0
-googleapis-common-protos==1.51.0
+gevent==20.5.0
 greenlet==0.4.15 ; platform_python_implementation == 'CPython'
-grpcio-tools==1.28.1
-grpcio==1.28.1
 gunicorn==20.0.4
 idna==2.9
 itsdangerous==1.1.0
 jinja2==2.11.2
-lnd-grpc==0.4.0
 lnurl==0.3.3
 markupsafe==1.1.1
-protobuf==3.11.3
-pydantic==1.5
-pylightning==0.0.7.3
+pydantic==1.5.1
 pyscss==1.3.7
 requests==2.23.0
 shortuuid==1.0.1