Upgrade the frontend to vue3

[CerealBoy]

Resolves #271

• Completely upgrade to vue3 including all deps
• Simplify the embedding of built content
• Fixing the display of the search box to better infer layout structure
• Change the header background colour to a specific value rather than generic

[github-actions]

Merging this branch will not change overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/cloudcloud/roadie/pkg/server	29.07% (ø)

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Coverage by file

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/cloudcloud/roadie/pkg/server/server.go	52.08% (ø)	48	25	23

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.