Develop installer update

[ninjamonkey198206]

Merged all scripts into a single cfg file, then split into further function type specific cfg files with their own update checks.

Added menu with options for previous individual script functions.

Added commenting in many locations.

Combined previous scripts into reusable functions where possible.

Added default config and service files, reducing the required output for those functions to a simple copy and sed command for each.

Added menu options for dev installs per Dinger and Silver.

Added option to select dev repo during dev install.

Added DH generation and config to nginx config files.

Added STS setting to nginx configs per https://syslink.pl/cipherlist/

Added check for localhost per #779

Updated gpg key import for repos to modern method, as previous method is now deprecated.

Added option to import existing cert, key, and ca chain cert using vim editor. Muahahahahahahaha!

Imported certs are created in the same location if letsencrypt certs are not generated.

Added input verification where appropriate to prevent user error during entry.

Added option for manual input of usernames and passwords.

Added option for Fail2ban install.

Added LetsEncrypt cert renewal function.

Added check to verify if user running script is tactical user.

Added check to verify tactical user has sudo privileges.

Added tactical user creation if it does not exist.

Added command-line argument usage for automated installs.

Included checks to ensure all args necessary are included, are valid, and in the correct format, or script will fail with an error message.

Removed need for prompts in troubleshooting function if nginx conf files exist, if not, prompt for input.

Added repo url verification.

Added DNS tests to hopefully ensure install won't occur if DNS not properly configured.

Reworked hostname and root domain input verification to allow for domains ending in .co.uk and similar.

Added troubleshooting, backup, and restore via cli args.

Added webroot letsencrypt certificate option with automatic post renewal service restart.

Added generation of log files for each major function/section.

Added sudo password cli arg for fully automated runs, with automated removal of script run command and passed password from history.

Added backup of existing nginx conf files (including default nginx.conf) during install, update, and restore.

Added default nginx.conf file to replace version shipped with OS, as it often has insecure options enabled by default.

[ninjamonkey198206]

Closing to reopen, as an update to clean up script and files using shellscript checker was "too much" at once...