Add: Rust bindings generate using bindgen

[chungquantin]

Generate bindings code using bindgen. Implement two simple methods to open / close database using the following ukv_database_init() and ukv_database_Free().

Contributors

• chungquantin

Added

• Database structure

struct Database {
 db: UkvDatabaseInitType
}

• Build bindings to cpp header file in include/ukv. To generate bindings code stored, use cargo build. build.rs includes code to build bindings using bindgen
• Support two APIs: ukv_database_init and ukv_database_free
• Add clippy, rust-fmt and editor config file for formatting and linting

Issues

• Can't generate bindings on file with linked source header. For example, generate on file blobs.h which includes ukv/db.h would throw error No header file found.