Display discords timestamps via <:t:timestamp_unix:f>

[LifeIsAParadox]

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Description

Fixes #543

Type of change

Please delete any options that are not relevant.

• Other
  use Discord timestamp format

https://discord.com/developers/docs/reference#message-formatting-formats

Checklist

• My code follows the style guidelines of this project
• I ran ESLint and other linters for modified files
• I have performed a self-review of my own code and tested it
• I have commented my code, particularly in hard-to-understand areas
  (including JSDoc for methods)
• My changes generate no new warnings
• My code needed automated testing. I have added them (this is optional task)

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[CommanderStorm]

First of all:

• please give the PR a descriptive title
• please actually run the Checklist (not only checking the boxes) ^^

About the functionality:
This kind of undermines the ability to set the timezone of the uptime server and instead hands that off to discord.

• The problem I see: is this transparent to the users or do we need to change this from "Time" to something like "Time (client-locale)" (I am not super happy with that as well)
• I have attached two comments which fix the formatting issues raised by check-linters
• Could you attach a before and after screenshot?
• Have you made sure that the code you wrote and the previos code is identical?
  From what I looked at, the time of the heartbeatJSON and the current time might be different. Could you use the timestamp all other notification providers use as well?
  The variable you are replacing gets created here:
  

  uptime-kuma/server/model/monitor.js

  Lines 1288 to 1290 in f0c54be

  	heartbeatJSON["timezone"] = await UptimeKumaServer.getInstance().getTimezone();
  	heartbeatJSON["timezoneOffset"] = UptimeKumaServer.getInstance().getTimezoneOffset();
  	heartbeatJSON["localDateTime"] = dayjs.utc(heartbeatJSON["time"]).tz(heartbeatJSON["timezone"]).format(SQL_DATETIME_FORMAT);

  
  As I read this code (and the lines previosly) "time" might be slightly different from the time of notification.
  Could you use the same time-reference as well?

[louislam]

Should convert the time from heartbeatJSON["time"], not Date.now()

[LifeIsAParadox]

Please excuse the wrong format, I didn't use ESLint properly, but I've fixed it now.

Here is the before/after pictures:

before	after

[LifeIsAParadox]

Should convert the time from heartbeatJSON["time"], not Date.now()

changed Date.now() to heartbeatJSON["time"]

[louislam]

I think the time is incorrect

I input <t:1697527649:f> manually, it could show the correct local datetime.

[CommanderStorm]

@LifeIsAParadox can you explain this difference? (I have not looked into this, but it seems a bit strange)

[CommanderStorm]

@LifeIsAParadox
Thanks for your work.
Given that louis has not gotten this to work correctly and there has not been any activity after that, I am going to close this PR.
If something changes (f.ex. if the reproduction of the feature starts working because Discord fixed a bug) we can reopen the PR. ^^