fix #207 add support for RedisModule_GetCurrentCommandName

[gkorland]

No description provided.

[oshadmi]

Will crash on redis prior to 6.2
(redis/redis#8792)
I suggest to check if available, and if not return "N/A" etc., or even better to allow it to fail.

[oshadmi]

Suggested change

	#[cfg(feature = "experimental-api")]
	pub fn current_command_name(&self) -> &str {
	unsafe {
	CStr::from_ptr(raw::RedisModule_GetCurrentCommandName.unwrap()(self.ctx))
	.to_str()
	.unwrap()
	}
	}
	pub fn current_command_name(&self) -> Result<String, RedisError> {
	#[cfg(feature = "experimental-api")]
	unsafe {
	match raw::RedisModule_GetCurrentCommandName {
	Some(cmd) => Ok(CStr::from_ptr(cmd(self.ctx)).to_str().unwrap().to_string()),
	None => Err(RedisError::Str(
	"API RedisModule_GetCurrentCommandName is not available",
	)),
	}
	}
	#[cfg(not(feature = "experimental-api"))]
	Err(RedisError::Str(
	"API RedisModule_GetCurrentCommandName requires feature 'experimental-api'",
	))
	}