Checks missing from pre_configure plugin

[wxtim]

Description

Checks which are in the post-install plugin are missing from the pre-install step:

• Warn about use of [jinja2:suite.rc (presumably [empy:suite.rc] too?).
• Warn about root-dir.

Reproducible Example

#!/bin/bash
set -x
DIR="${HOME}/cylc-src/tmp.230"
mkdir -p "${DIR}"
cat > "${DIR}/rose-suite.conf" <<__HERE__
root-dir = ~/foo

[jinja2:suite.rc]
__HERE__

touch "${DIR}/suite.rc"

cylc validate "${DIR}"
# ... no warnings

cylc install "${DIR}"
# ... warnings

test.txt

Expected Behaviour

Cylc Rose should display this warning prior to installation.

[wxtim]

Actual cause described in cylc/cylc-flow#5582 - which should close this tickets