[feature] add min and max at static methods

[itsmuntadhar]

First, I would like to say thanks for the great work!

We've been looking into ULID to use instead of UUID/GUID in our projects and figured we could get rid of the dedicated "CreatedAt" column/prop that we usually have.

To make querying easier, we thought such methods would be great to have in the lib so we could do something like

var anHourAgo = DateTimeOffset.UtcNow.AddHours(-1);
var idGte = Ulid.MinAt(anHourAgo);
queryable = queryable.Where(x => x.Id >= idGte);

Was also looking into writing a couple more extensions, maybe in another PR.
Basically

DateTimeOffset.UtcNow.NewUlid();
DateTimeOffset.UtcNow.MinUlid();
DateTimeOffset.UtcNow.MaxUlid();

Thanks again

[RobThree]

Hi!

I'm not sure why I missed this PR and never replied. I'll look into this soon(-ish) and get back to you. Just wanted to let you know your PR is appreciated and I apologize for missing it.

[itsmuntadhar]

Things happen :)

Will look into solving the conflicts shortly

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Copilot]

Pull Request Overview

This PR introduces new static methods for generating ULIDs based on a specific DateTimeOffset, allowing users to retrieve the minimum and maximum ULID values for a given time.

• Added Ulid.MinAt and Ulid.MaxAt static methods in Ulid.cs that generate ULIDs with fixed byte arrays for minimum and maximum values.
• Updated the MinValue and MaxValue fields to use the new methods.
• Provided corresponding DateTimeOffset extension methods (NewUlid, MinUlid, MaxUlid) in DateTimeExtensions.cs.
• Updated global.json and VS Code settings files for configuration.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

File	Description
global.json	Updated SDK version configuration.
NUlid/Ulid.cs	Added static methods for ULID generation with min/max values and updated MinValue/MaxValue fields.
NUlid/DateTimeExtensions.cs	Added extension methods for DateTimeOffset to generate ULIDs.
.vscode/settings.json	Configured default solution for VS Code.

[Copilot]

[nitpick] Consider extracting the fixed byte array [0, 0, 0, 0, 0, 0, 0, 0, 0, 0] into a static readonly field to avoid new allocations on each call.

Suggested change

	=> new(time, new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 });
	=> new(time, MinBytes);

[Copilot]

[nitpick] Consider extracting the fixed byte array [255, 255, 255, 255, 255, 255, 255, 255, 255, 255] into a static readonly field to avoid new allocations on each call.

Suggested change

	public static Ulid MaxAt(DateTimeOffset time)
	=> new(time, new byte[] { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 });
	private static readonly byte[] MaxBytes = { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 };
	public static Ulid MaxAt(DateTimeOffset time)
	=> new(time, MaxBytes);