[IMP] improve icons and views

addons/account_asset/account_asset_view.xml

addons/account_followup/account_followup_customers.xml

addons/account_payment/account_payment_view.xml

addons/account_voucher/account_voucher_view.xml

addons/crm/crm_lead_view.xml

addons/crm/crm_phonecall_view.xml

addons/crm_project_issue/project_issue_view.xml

addons/email_template/email_template_view.xml

addons/fleet/fleet_view.xml

addons/gamification/views/challenge.xml

addons/hr_contract/hr_contract_view.xml

addons/hr_evaluation/hr_evaluation_view.xml

addons/hr_payroll/hr_payroll_view.xml

addons/hr_recruitment/hr_recruitment_view.xml

addons/hr_timesheet/hr_timesheet_view.xml

addons/hr_timesheet_sheet/hr_timesheet_sheet_view.xml

addons/marketing_campaign/marketing_campaign_view.xml

addons/point_of_sale/point_of_sale_view.xml

addons/project_long_term/project_long_term_view.xml

addons/purchase/partner_view.xml