Upgrade Odoo modules from v10 to v15

Dear freelancer, We have 8 Odoo modules that need to be upgraded from v10 to v15. These modules represent all in all 3000 lines of Python code, and 2070 lines of xml codes, comments included. They come from different sources : in-house development by beginning Odoo developper, external freelance, purchase. Here is the list : project_task_run_stop : add a start / stop button to track time spent on a task, and add it to timesheet project_task_auto_assign : assign a task to a user when the task enters a certain stage message_publish_backend : add the option to choose whether a message is published on the portal, or is only for internal users direct_email_to_project : (one of the most important for us) : task get an extra "mail" button, which makes it possible to write to the task from any external email, just like if the task chatter had been used --> we use this to have normal email conversations, but keep the task in copy, and find all the conversation in the task chatter charbon_timesheet_privacy: add a button to timesheet entries to decide if they are visible on the portal or only internal charbon_project_mails : change notifications and mail layouts related to project management. Make internal only emails having certain keyworkds charbon_project : add custom fields and views to project.task and project.project