[Dataset]: Iterate through benchmark dataset once

[parfeniukink]

issue link: https://github.com/neuralmagic/guidellm/issues/44

Summary:

• --max-requests CLI parameter now supports the dataset value.
• MaxRequestsType(ParamType) is used as a custom click param type to validate input data
• RequestGenerator(ABC) now includes the abstract __len__ that corresponds to the length of the dataset if it is supported.
• Unit tests are added
  • Smoke tests are added
• guidellm/utils/text.py is fixed. There is no reason to check if the file start with the 'http' string. Basically this is a Bug since you never read a text file properly because of old if/else condition.

[parfeniukink]

@philschmid Hey there. Could you install the version of the branch parfeniukink/issues/44 and tell me if works for you?

[philschmid]

Hey Guys, any idea on when we could get this merged?