Improve cache locality and perf of DeepGru on CPU (#13582)
### Description
<!-- Describe your changes. -->
Introduce Gemm weights pre-pack.
### Motivation and Context
A 1-P customer requested a performance improvement for DeepGru which
consumes a bulk of CPU in their model. This provides measurable
performance improvements.
Customer model numbers.
gru: mean = 356 us; 1ms = 99.8 prctile; 99th prctile = 665 ms
(yuslepukhin/deep_gru_opt)
main: mean = 375 us; 1ms = 99.8 prctile; 99th prctile = 695 ms (where
yuslepukhin/deep_gru_opt branched off main)
1.13.1: mean = 391 us; 1ms = 99.6 prctile; 99th prctile = 744 ms
