UP to SDB version 2.0

[kotolex]

• both http and ws connections lost signin, signup, authenticate, invalidate methods, sign in now happen under the hood on connecting
• USE method for http just adds headers "surreal-db" and "surreal-ns" for http-requests
• websocket client under the hood uses explicit "sec-websocket-protocol"="json" header
• http now uses rpc-protocol instead of different endpoints and methods
• for root user now you should connect only with credentials and then call use method (see examples)
• you can now specify access method on connecting via a Surreal/Database object
• now use Bearer instead of Basic for Authorization
• database argument is now optional for USE method, but raises for websocket if a database is not specified
• all QL-statements now have SurrealQL Syntax in documentation for class
• all DEFINE statements now have COMMENT finished statement
• now DEFINE TOKEN use Algorithm enum
• Database object can be created from active connection with Database.from_connection(connection)
• Connection can be extracted from Database with Database.get_connection()
• improve DEFINE ANALYZER, now it uses predefined methods for tokenizers and filters, and has documentation for all of them
• SELECT statement can use TEMPFILES clause on all levels except EXPLAIN (which is the last one)
• update DEFINE USER statement
• add UPSERT statement
• add DEFINE ACCESS JWT and DEFINE ACCESS RECORD statements
• add REMOVE ACCESS statement
• add ALTER TABLE statement
• add ENFORCED statement for DEFINE TABLE
• add CONCURRENTLY statement for DEFINE INDEX
• deprecate DEFINE TOKEN-REMOVE TOKEN and DEFINE SCOPE-REMOVE SCOPE
• let and unset now raises CompatibilityError for http
• add upsert method to Connection
• all DEFINE statements except SCOPE/TOKEN now have OVERWRITE clause
• Connection objects now store token after authorize
• more examples and tests, fix old examples
• fix Readme, add compatibility table