Grid/columns: Replace new lines with the HTML break when `multiLine' is enabled

Example config:

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<template match-pattern="icinga-(service-template|.+-service-problems)">
    <fields>
        <field name="plugin_long_output">
            <datasource>
                <parameter name="field">SERVICE_LONG_OUTPUT</parameter>
            </datasource>
            <display>
                <parameter name="visible">true</parameter>
                <parameter name="label">Long output</parameter>
                <parameter name="jsFunc">
                    <parameter>
                        <parameter name="namespace">Cronk.grid.ColumnRenderer</parameter>
                        <parameter name="function">customColumnPerfdataSanitized</parameter>
                        <parameter name="arguments">
                            <parameter name="multiLine">1</parameter>
                        </parameter>
                    </parameter>
                </parameter>
            </display>
            <filter>
                <parameter name="enabled">false</parameter>
            </filter>
            <order>
                <parameter name="enabled">false</parameter>
                <parameter name="default">false</parameter>
            </order>
        </field>
    </fields>
</template>

refs #2653