Node details page improvements

[Thierry61]

• Corrected empty "HOST" field
• Added a link from "PEERS" field to Peers page
• Redefined forksUrls as a multiline variable (more readable)
• Added tooltips

[Thierry61]

Hi @janoside. Are you not interested by the PR? I have been proposing these features for about 3 weeks, see #542 previous PR (I recreated a new PR because merge from upstream didn’t work as I expected):

• Empty HOST field can be observed right now in your live demo:
• Linking peers page from PEERS field seems a right place to do it:
• Tooltips are a useful addition to this page. English is not my native tongue, so please correct them if you find better formulations (as "Allow edits by maintainers" is checked)

[janoside]

@Thierry61 I like the PRs! Sorry for the delay. Recently finished up other obligations and coming back to merge PRs and try to get another release out ASAP.