Added cursor pointer when hovering a keyword in Related Keywords and
added relevant tooltip for the better user experience.

Renamed classes:
js_seo_keyword_suggestion -> o_seo_keyword_suggestion
js_seo_suggestion -> o_seo_suggestion

task-2070946
closes odoo/odoo#36709

Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>