Allow extracting EnvFunction local values as a read only map

Description

This is to support thread EnvFunction thread local transfer across threads in GeoServer (think secondary rendering thread, but also WPS execution thread pools, and more to come in the future as the world moves to more towards asynch invocations for long tasks)

Environment

None

Assignee

Andrea Aime

Reporter

Andrea Aime

Triage

None

Components

Fix versions

Priority

Medium
Configure