[EP-Perf-Dashboard] Reduce script excessive output (#13562)
### Description
Properly cleans up all temporary resources created while running
benchmarks.
Details:
- Dump all temporary artifacts (TRT engines, TRT profiles, inference
profiles, fp16 models) into a temp directory in `/tmp/`. Each model/EP
combination has its own temp directory that is deleted after validation
and benchmarking.
- Allow running both validation and benchmarking in one invocation of
the benchmark.py script. This is necessary to allow the benchmarking
step to reuse artifacts (e.g., TRT engines) created during validation.
Before this PR, we ran validation on all model/EP combinations before
running benchmarks on all combinations again. This required us to keep
all temporary artifacts for all model/EP combinations throughout the
entire run (expensive).
- Create individual functions for validation and benchmarking (split-up
large function that did it all)
### Motivation and Context
The EP Perf pipeline failed to run because the script generated too much
output and the VM ran out of disk space.
