Derrick/bt 11715 engine builder templates

[derrick-yyang]

TRTLLM Engine Builder exampels for llama3.1 8b and 7b.

Targeted 3 use cases for each model:

• high throughput (with a reasonable latency)
• Large context (be able to handle large context with reasonable benchmarks)
• Low ttft (optimized for a small TTFT)

[linear[bot]]

BT-11715 Prepare a set of engine builder templates for common configurations