Initial commit: Pezkuwi SubQuery indexer

- pezkuwi.yaml: Relay chain staking indexer (rewards, slashes, pools, transfers, era info)
- pezkuwi-assethub.yaml: Asset Hub indexer (NominationPools, asset transfers)
- GraphQL schema for staking data entities
- Handler mappings from Nova SubQuery base

scripts/python_scripts/requirements.txt

@@ -0,0 +1,34 @@
+anyio==3.6.2
+attrs==22.2.0
+certifi==2022.12.7
+chardet==5.1.0
+charset-normalizer==3.0.1
+DataProperty==0.55.0
+exceptiongroup==1.1.0
+h11==0.14.0
+httpcore==0.16.3
+httpx==0.23.3
+idna==3.4
+iniconfig==2.0.0
+Jinja2==3.1.2
+MarkupSafe==2.1.2
+mbstrdecoder==1.1.1
+packaging==23.0
+pathvalidate==2.5.2
+pluggy==1.0.0
+pytablewriter==0.64.2
+pytest==7.2.1
+python-dateutil==2.8.2
+python-telegram-bot==20.0
+pytz==2022.7.1
+PyYAML==6.0
+requests==2.28.2
+rfc3986==1.5.0
+six==1.16.0
+sniffio==1.3.0
+tabledata==1.3.0
+tcolorpy==0.1.2
+tomli==2.0.1
+typepy==1.3.0
+urllib3==1.26.14
+wget==3.2