* feat: export content utility (wip)

* feat: export navigation + groups + users

* feat: export comments + navigation + pages + pages history + settings

* feat: export assets

* saml auth: `authnContext` must be a list now

This fixes

    this.options.authnContext.forEach is not a function

when trying to login via SAML on wiki-js 2.5.281.

Reason for that is that `authnContext` must be a list now which is
apparently a breaking change that was missed while upgrading
passport-saml[1].

Resolves #5289

[1] https://github.com/node-saml/passport-saml/pull/615

* fix(auth): split authnContext for SAML authenticaiton module
Co-authored-by: Nicolas Giard <github@ngpixel.com>

git has the quotopath option enabled by default,
filepaths with unicode characters will be escaped,
causing the wiki to not handle changes.

Co-authored-by: Nicolas Giard <github@ngpixel.com>

* feat: Add option to specify default value to env var expansion

* fix: remove unused capturing group for env var replacement
Co-authored-by: Nicolas Giard <github@ngpixel.com>

* fix: Use logger for logs using console logging

* feat: Add option to configure JSON logging

* fix: use generic logFormat instead of json specific

* fix: use logFormat for docker config

* fix: use logFormat to build winston formatters
Co-authored-by: Nicolas Giard <github@ngpixel.com>

* permit bodyParserLimitSize configuration

set bodyParserLimitSize by default to 1mb
permit modifications by environment variable

* fix: use bodyparserlimit config with fallback default
Co-authored-by: Nicolas Giard <github@ngpixel.com>