Able to select multiple choices in the drop down when using a list for a BOE section

Feature Request: Multi-select options for BOE section lists

Summary:
Enable users to select multiple values from a list-based BOE section (drop-down) in the BOE View, so that a single section can accurately capture scenarios where more than one option applies.

Problem Statement:
Currently, when configuring a BOE section to use a list, the control only allows a single selection from the drop-down. This is limiting for use cases where multiple choices are simultaneously valid (e.g., multiple contract types, funding sources, or applicable categories). Users are forced to either pick just one value (losing important detail) or create redundant sections/fields to capture all applicable options, which is inefficient and harder to maintain.

Proposed Solution:
Support a multi-select mode for list-based BOE sections in the BOE View.
When a BOE section is configured to use a list, provide an option to specify whether the field is single-select or multi-select.
In multi-select mode, the UI should allow users to select more than one list value (e.g., via checkboxes, pill-style selections, or a multi-select drop-down pattern).
Ensure that selected values are clearly displayed and can be easily added, removed, or reordered (if ordering is relevant).
Persist all selected values for reporting, downstream integrations, and exports in a consistent, structured format (e.g., delimited text or array, depending on the data model).
Maintain backward compatibility so existing single-select BOE list sections continue to behave as they do today unless explicitly changed to multi-select.

Benefits:
Accurately models real-world scenarios where multiple options apply to a single BOE section.
Reduces the need for redundant fields or workaround configurations to capture multiple values.
Improves data quality and completeness by allowing users to record all relevant choices in one place.
Enhances usability of the BOE View by aligning list behavior with user expectations for modern multi-select patterns.
Supports more robust reporting and analysis based on complete, multi-valued BOE section data.