Add more choices to jemlistevents

[Heklaterriol]

While working on the issues #1914, I came up with some new choices we could add to jemlistevents:

• open date events
• all events (except trashed)
• ongoing events

I'll try to implement them and then present them here for you to check out

[Heklaterriol]

@mckillo and @jojo12 :

Please check out the jemlistevents plugin.
https://github.com/jemproject/JEM-Project/tree/JEM-4.3.3-jemeventlist

Here is the installation file:
https://raw.githubusercontent.com/jemproject/JEM-Project/refs/heads/JEM-4.3.3-jemeventlist/plugins/plg_content_jemlistevents.zip

What is changed in the jemlistevents plugin:

• jemlistevent unfinished does not show events of today #1914 is fixed
• the displaying conditions of the events is exact now, including the time. E.g. "unfinished" is exactly to the end time of the event
• I added 3 new types: "ongoing": Ongoing events, taking place now, "open": Open events with no date/time, "all": All events (past, ongoing, upcoming and archived)

[jojo12]

Works fine. I continue to test

[Heklaterriol]

I actually wanted to add a time offset for both the start time and the end time, which controls the display duration of the events.
But when I was working on it I realized that this is not so trivial, e.g. if the start time is moved forward and the time backward, they may become contradictory.
It's almost done, but I think it's too complicated for the users.