docs: developer_guides: enrich wov-ecns guide context and fix fig223 collision

- Fix collision in Figure 223 (wov_ecns_pipeline_architecture.svg) by
  moving Pipeline 107 box down below Slot 2 and shifting the Notifier Bus.
- Add comprehensive technical context for Notifier registration and
  dispatch, including real-time execution constraints and lifecycle rules.
- Detail component interface implementation, multi-pin buffer processing,
  pointer advancement, and IPC configuration handling in Step 2.
- Provide an in-depth explanation of input/output buffer sizes (ibs/obs),
  scheduler threshold calculation, buffer allocation, and topology
  contract validation in Step 3.
- Expand single-sentence sections across the WOV-ECNS guide with detailed
  technical guidance for WOV replacement, cross-core scheduling, NHLT
  preprocessor usage, ACPI driver override, and hardware testing.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo