Remove the Reference to Sharprompt and Replace Usage with the Spectre.Console API (old Spectre.CLI API)

[MokoSan]

Related to #39, now that we are planning to incorporate the Spectre.Console API, makes sense to replace all usage of the Sharprompt API for the prompts and remove the reference altogether.

These include:

1. Creating a new Config which involves:
   • Selecting the appropriate GC Rows via MultiSelectionPrompt.
   • Selecting the Period of the for the timer via TextPrompt.
   • Selecting the Min. GC Pause Duration via TextPrompt.
2. Filling in the Default Values if a configuration is meant to be overwritten:
   • For the MultiSelectionPrompt This done by using the Select<T> functionality.