[Feature] Add links to webpage for papers with arxiv and doi

[charlieJ107]

This PR implemented #469

I added two link button that open the system default external browser to open the arxiv or doi link based on the arxiv and doi properties in PaperEntity. These two buttons only shows when these two properties existed.

I also remove the formatOnSave settings in .vscode/settings.json because the format behaviour may vary on different platform, which may mess up the format of entire file.

[charlieJ107]

FYI, here're some screenshots:

[GeoffreyChen777]

It looks good. I’m thinking what about merging this with the source code section to get a section called ‘online resource’?

[charlieJ107]

It looks good. I’m thinking what about merging this with the source code section to get a section called ‘online resource’?

Should it be in the same slot with the publisher (slot 1) or at the bottom of the paper details (slot 3)?

[GeoffreyChen777]

We leave the publication text in the publication section. And we move the link buttons, such as the ‘DOI’ one in the screenshot to the source code section and we rename the source code section to ‘online resource’ section.

[charlieJ107]

Now it's like this:

[GeoffreyChen777]

Looks good.👍🏻 thanks.

I will review the code once I back from my trip.

[GeoffreyChen777]

I fixed some bugs 9b6c02f , now everything looks good to me.