HDDS-11609. Switch to Recon v2 UI as the default UI

[devabhishekpal]

What changes were proposed in this pull request?

HDDS-11609. Switch to Recon v2 UI as the default UI

Please describe your PR in detail:

• Currently the default UI on visiting Recon is the V1 UI
• This PR changes the default UI to show the new v2 UI by default and enable the UI switching for users that want to use the old UI
• The heatmap page for this points to the v1 Heatmap UI even when v2 UI is enabled which would be changed to point to new heatmap page once that is prepared.
• As a part of this PR we are also adding a new improved 404 page design.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-11609

How was this patch tested?

Patch was tested manually

New UI is the default UI (Switch is not toggled)

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Old UI (Switch is toggled)

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New 404 page