v0.8.2

Full Changelog: v0.8.1...v0.8.2

• Fix: a critical value of the JwsHeaderSet/JweHeaderSet should not be encoded by BASE64.
• Fix: x509_certificate_chain must be encoded in STANDARD not STANDARD_NO_PAD or URL_SAFE_NO_PAD.
• Fix: Improve a BASE64 value checking.