1918719 - Implement DEVELOPER_TOOLS in runtime.getContexts()

Status: NEW

(WebExtensions :: General, enhancement, P3)

Description

[Rob Wu [:robwu]]

We should add a DEVELOPER_TOOLS context to the runtime.getContexts() implementation.

When we implemented runtime.getContexts() in bug 1875480, we intentionally omitted devtools contexts since they were not specified yet: https://searchfox.org/mozilla-central/rev/ab8043ccefe85c30ef78b97193918934d6aa93d1/toolkit/components/extensions/ExtensionParent.sys.mjs#841-845

In https://github.com/w3c/webextensions/issues/670 the devtools context was discussed, resulting in a PR at https://github.com/w3c/webextensions/pull/675 that updates the proposal at https://github.com/w3c/webextensions/blob/main/proposals/runtime_get_contexts.md