Add BeforeMarketOpen() and AfterMarketClose() date rules

[Marinovsky]

Description

Add BeforeMarketOpen() and AfterMarketClose() date rules using the already implemented AfterMarketOpen() and BeforeMarketClose() date rules.

Related Issue

Closes #8106

Motivation and Context

With this change users will be able to use a date rule that fires $x$ number of minutes before the market opens or $x$ number of minutes after the market closes.

Requires Documentation Change

This change might require a change to documentation briefing the users on this new feature.

How Has This Been Tested?

I created two unit tests, one using BeforeMarketOpen() and the other AfterMarketClose(), that assert the even times created with the time rules are the expected ones.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Refactor (non-breaking change which improves implementation)
• Performance (non-breaking change which improves performance. Please add associated performance test and results)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Non-functional change (xml comments/documentation/etc)

Checklist:

• My code follows the code style of this project.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My branch follows the naming convention bug-<issue#>-<description> or feature-<issue#>-<description>

[Martin-Molinero]

Thank you 👍