[Extensibility Request] issue 30173: add integration events to Sales Line Discounts page

[AleksandricMarko]

Summary

The author is building an extension on top of page 7004 "Sales Line Discounts" with additional fields backed by page-level global variables, and needs extensibility hooks that were not previously available. Specifically, they need to influence record filtering during filter setup (with access to the page/rec context) and to resolve the filter description for item type filter values the base application does not handle. This PR adds two integration events on the page so partners can extend these flows without modifying base code.

Source issue repository: microsoft/ALAppExtensions; issue number: 30173

Changes Made

• OnSetRecFiltersOnBeforeCurrPageUpdate - new integration event raised in SetRecFilters after all record filters are applied and before CurrPage.Update, exposing the sales line discount record and the current item type filter so subscribers can apply additional filtering. Uses IncludeSender = true (matching existing events on the page) to give subscribers access to the page instance.
• OnGetFilterDescriptionCaseElse - new integration event raised from the else branch added to the ItemTypeFilter case in GetFilterDescription, letting subscribers supply a custom source table name and item filtering for item type filter values other than Item and Item Discount Group.
• The event parameters use the page's current ItemTypeFilter option type; the requested enum "Item Type Filter" is tracked separately (issue #30170) and does not yet exist in the codebase.

Fixes AB#637953

[github-actions]

Copilot PR Review

Iteration 1 · Outcome: completed

Knowledge source: https://github.com/microsoft/BCQuality@809af9708e265f110ced6752fd8f2e40f1efc820

Findings by domain

Findings split into Knowledge-backed (cite a BCQuality article) and Agent (the agent's own judgement, no matching BCQuality rule).

Domain	Findings	Knowledge-backed	Agent	Inline	Fallback
Accessibility	1	1	0	0	0
Agent	5	0	5	0	0
Other	2	2	0	0	0

Totals: 3 knowledge-backed · 5 agent findings.

Orchestrator pre-filter (2 file(s) excluded)

• layer-disabled (knowledge) : 2 file(s)

_{Findings produced by the Copilot CLI agent against BCQuality at 809af9708e265f110ced6752fd8f2e40f1efc820. Reply 👎 on any inline comment to flag false positives.}