Fix: hide header and sidebar on the Export page

[katspaugh]

What it solves

The Export page is the only page that will be accessible in the old app for some time.
We need to prevent navigation to any other react route from it.

How it solves it

I'm hiding all header elements except for the logo (which now links to the new app), and the contents of the sidebar.

[github-actions]

CLA Assistant Lite All Contributors have signed the CLA.

[github-actions]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	2	0
Ignored	0	N/A

• Result: ✅ success

• Annotations: 2 total

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[warning] @typescript-eslint/explicit-module-boundary-types

Require explicit return and argument types on exported functions' and classes' public class methods

• src/components/layout/Page/index.tsx Line 7 - Missing return type on function.
• src/components/layout/Page/index.tsx Line 7 - Object pattern argument should be typed with a non-any type.

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^{Report generated by eslint-plus-action}

[coveralls]

Pull Request Test Coverage Report for Build 4004725391

• 1 of 8 (12.5%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.03%) to 41.846%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/routes/export/Export.tsx	0	7	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/routes/export/Export.tsx	1	0%

Totals
Change from base Build 3874020678:	-0.03%
Covered Lines:	4779
Relevant Lines:	10428

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💛 - Coveralls