Openpecha

Fix
* **ocr-postprocessing:** The bounding polys are sorted before text extraction ([`3537a3f`](https://github.com/OpenPecha/Openpecha-Toolkit/commit/3537a3f76e26ea97eb1d29717172dce0fd255ed6))

Fix
* Set openpecha-data org name from env var only ([`e2e9052`](https://github.com/OpenPecha/openpecha-toolkit/commit/e2e9052827090b6e936f8d60dc3e28a2735ec4eb))

Fix
* **core:** Remove empty dict as default value in OpenPecha class ([`e863543`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/e86354361807ca8dec6ed2be338c551cd378eeda))

Fix
* **metadata:** Add seperate metadata classes for pecha types ([`904f926`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/904f9264c2e895e1ff9f9e85abb15109f70177e7))
* **core:** Replace source id with initial id ([`ca083be`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/ca083be3f723ed3d9015b92e145c6830def16a3b))
* **core:** Add source and diplomatic id generator ([`24549dd`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/24549dd5c710caa506c022f999ab74a197564fed))

Fix
* **core:** Add copyright and license in metadata ([`1db55da`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/1db55dad74631ee98b26d8d3127c598ec310c82e))
* **core-metadata:** Typos ([`d1b44f0`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/d1b44f03a88b2275b3122bb3505b52141f59c964))
* **core:** Move metadata model into metadata.py module ([`9f6f1a3`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/9f6f1a3c51a8b3f0b85f482393f36f4bf6d0b204))

Documentation
* **metadata:** Add copyright and license to metadata ([`b15ab56`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/b15ab56e5acdcb055887c5ad315a8bc5473d3f07))

Fix
* **serializer:** Apply index updated ([`be9a831`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/be9a8311939a5b9cdfc0947e35af3b5767cddcda))
* **serializer:** Vol id variables are renamed as base_id and vol keyword in span are changed to base ([`1d6898d`](https://github.com/OpenPecha-dev/openpecha-toolkit/commit/1d6898d9be7376963f865ec3da56547862a906c9))