Render inline SVG inside buttons in order to allow CSS styling. Define SVG icons design for normal/hover status applying the same colors as default text buttons. In order to support multi-colors SVGs, this commits will affect inner shapes in different ways: - '.o_graphic' shapes: will gets the UI btns colors (default/hover) - '.o_subdle' shapes: will gets a slightly reduced default text color Shapes without '.o_graphic/.o_subdle' classes will be rendered normally, as defined in the svg code. Part of https://github.com/odoo/odoo/pull/54913 task-2157252 Co-authored-by: qsm-odoo <qsm@odoo.com>