fix: reload of iframe on dpg tab change

[pranav-deshmukh]

Description

Fixes GAZ-136

Improves the behavior of DPG iframes when navigating between different tabs or DPGs. The goal is to ensure a seamless user experience by preserving the state of each iframe.

Changes Made

• Persisted the current step URL of the DPG iframe when the tab changes.
• When a user navigates to a different DPG and then comes back, the previous state of the iframe (e.g., form inputs, current view) is restored.
• Prevented unnecessary iframe reloads when switching between DPGs, ensuring faster and smoother transitions.

Demo video:

demo.for.pr.mp4

How to Test

1. Start filling a form in one DPG.
2. Navigate to another DPG tab.
3. Come back to the original DPG tab.
4. Observe that the form state and current view are preserved, and the iframe doesn't reload.

[abhinav-1305]

Thanks @pranav-deshmukh