获取本地文件MIMEType

上传文件的时候需要获取文件的MIMEType，可以使用以下接口：
其中path为文件的本地路径

+ (NSString *)fileMIMETypeURLSessionWithPath:(NSString *)path {
    NSURL *url = [NSURL fileURLWithPath:path];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
    __block NSString *mimeType = nil;
    NSURLSessionTask *task = [[NSURLSession sharedSession] dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        mimeType = response.MIMEType;
        dispatch_semaphore_signal(semaphore);
    }];
    [task resume];
    dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    return mimeType;
}