Updated `CreateEnvelopeWizardPopup.razor` to enforce consistent popup dimensions by setting height properties to `85vh` and disabling scrolling.
Enhanced `sender-page.css` with new classes to manage flexible layouts and scrolling behavior for the wizard's stepper and step content. Removed fixed height and scrolling constraints from `.sender-create-wizard__receiver-existing-list` for better layout flexibility.
These changes improve the user experience by ensuring consistent dimensions, reducing unnecessary scrolling, and maintaining a structured layout.