Revise sidecar issue template for Entra ID (#3577)

Updated the issue template for Entra ID sidecar to include specific fields and improve clarity.

Author: jennyf19

.github/ISSUE_TEMPLATE/sidecar_issue.md

@@ -0,0 +1,23 @@
+---
+name: Entra ID sidecar issue
+about: Submit a bug or feature request for the Entra ID sidecar
+title: "[Entra ID sidecar] "
+labels: sidecar, needs attention, untriaged
+assignees: ''
+
+---
+
+**Is your feature request or bug related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...].
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.
+
+**Are you using a language adapter to call the sidecar?**
+Can you provide a repro of the issue?