feat: Less obtrusive clock close button

[sulkaharo]

• Close button color is much dimmer and changes color appropriately in the color face
• HIDE_CLOCK_CLOSEBUTTON setting to hide the button altogether (set to TRUE or ON to hide buttons altogether)
• Fix CSS for toolbar positioning in the main view
• Fix documentation on the clock URLs and add mention of the setting

[PieterGit]

Hate to be nitty gritty. We don't have HIDE_* environment variables yet, but we do have SHOW_*.
Shouldn't we use SHOW_CLOCK_CLOSEBUTTON with a default of true to be consistent?

[sulkaharo]

@PieterGit changed

[unsoluble]

Still need to add for the record that the buttons on the clock views aren’t actually necessary in any situation, but I guess I’ve lost this one. :)

[unsoluble]

Also though: This one should be pushed out now, not left for 0.13 — the toolbar spacing offset in the main view actually breaks functionality.

[PieterGit]

@unsoluble can you confirm that this PR works as expected (although you had like a different default). Depending on users knowing the Apple gestures is not a good userinterface thing. Nightscout should be usable withouth Apple features. I noted clock stuff still is not token-based proof, so I can't test it.

[unsoluble]

Users don't need to know Apple gestures to use the site in nearly every single use case. In the one specific situation where an iOS 12 user has pinned the main site to the home screen, and then ventures to a clock view from there, a gesture is required to get back to the main view. Honestly I'd wager this navigation path essentially never happens — adding a UI element with a controlling variable for a 0.00001% edge case like this seems like brutal overkill to me.

(I wrote the clock-color view; I know what its intended purpose is, and adding visual clutter by default is not good.)

If we absolutely must have this extra UI control in there as an option, I strongly suggest we default it to false, as people have been using these views for years without a button, and having one suddenly appear is bad. We can make it clear in the docs how to enable the button for those who for some reason feel they need it.

Will test when I get a chance, but probably can't be till later tonight.

[unsoluble]

(#4788 should be included in this too.)

[unsoluble]

Tested this branch — LGTM. If we default SHOW_CLOCK_CLOSEBUTTON to false, we can call it a truce. :)

[unsoluble]

We’re going with a false default though, right?