[IMP] Sales: onboarding

[FIX]improve domain and override create method in product attribute value.

[IMP]Added placehoder in comment field,seted create and delete false in tree view of attribute value

[IMP]Added form view for attribute values and bind with action

[REM]Removed unused code as per spec changed

[REM]Removed unused code for product attribute values and rechange placeholder for purchase.

[REM]Removed changed placeholder from website quote.

[IMP]Improved typo
If it is used only for name_search then you should override name_search but in this scenario you can put two field and set proper attrs to make it visible invisible and both will have different domain, like below..
<field name="title" options='{"no_open": True}' nolabel="1" colspan="0" domain="[('domain', '=', 'partner')]" context="{'is_company': is_company}" attrs="{'invisible': [('is_company','=',False)]}"/>
<field name="title" options='{"no_open": True}' nolabel="1" colspan="0" domain="[('domain', '=', 'contact')]" context="{'is_company': is_company}" attrs="{'invisible': [('is_company','=',True)]}"/>

Remove overridden _search