Odoo Release Updates

[IMP] test_lint{,_enterprise}, *: Index `Many2one` fields in `related` fields

[FIX] marketing_automation: fix typo in test

[IMP] mass_mailing: make view in browser a builder option

Adds .this prefix to template variables across codebase for OWL3 compatibility.

[REF] *: run rendering context migration script again

[FIX] marketing_automation: add required body_html based on body_arch

[FIX] marketing_automation: server error when deleting activity's mailings

[REF] *: run rendering context migration script

[REF] *: Run script to replace t-ref by t-custom-ref

[FIX] marketing_automation: add required body_html based on body_arch

[IMP] utm: improve and generalize UTM trackers data

[REF] documents,marketing_automation: move t-call on its own t element

[REF] *: remap useState import to owl2/utils

[REF] *: remap useRef import to owl2/utils

[REF] *: remap useSubEnv import to owl2/utils

[REF] *: Replace useEffect with useLayoutEffect for owl3 migration

[IMP] *: rename "Cancel" to "Discard"

[REF] *: no more a[href="#"] in notebook

[FIX] marketing_automation: fix disappearing of input in campaingn test

[FIX] *: Fix public docstrings

[ADD] *: add apps icons

[FIX] marketing_automation: make email from and reply to fields editable

[IMP] *: rename "Cancel" to "Discard"

[IMP] appointment, *: rename the o_editable class by o_savable

[FIX] marketing_automation: prevent error on removing interval type in activity

[CLN] *: manifests

[FIX] *: automaticaly set legacy at_install

[IMP] base,all: remove deprecated 't-esc' ir.qweb directive

[FIX] mass_mailing(_themes): increment mass_mailing snippets vxml

[IMP] marketing_automation, *: fine-tune onboarding sample