feat(core): add models for institution

src/FiscalOS.Core/Accounts/InstitutionMetadata.cs

@@ -0,0 +1,15 @@
+namespace FiscalOS.Core.Accounts;
+
+public abstract class InstitutionMetadata : Entity
+{
+  private readonly string _type;
+
+  public string Type => _type;
+
+  public Guid InstitutionId { get; init; }
+
+  protected InstitutionMetadata(string type)
+  {
+    _type = type;
+  }
+}