0c71e8b5b7
(This reintroduces the change in 9f84230c that was later reverted by
67b0b33a.)
frontend-platform supports runtime configuration since 2.5.0 (see the PR
that introduced it[1], but it requires MFE cooperation. This implements
just that: by avoiding making configuration values constant, it should
now be possible to change them after initialization.
Almost all changes here relate to the `LMS_BASE_URL` setting, which in
most places was treated as a constant.
[1] https://github.com/openedx/frontend-platform/pull/335