[Feat]: SMTP datasource - Offer to choose SMARTTLS vs TLS

[coronawalrus]

Is your feature request related to a problem? Please describe.
I tried to create a SMTP datasource using TLS (not SMARTTLS) on port 465, without success.
It's only after digging the source code (https://github.com/lowcoder-org/lowcoder/blob/db7aae37ded3c4bf64bfa21042aa8787b984fd9c/server/api-service/lowcoder-plugins/smtpPlugin/src/main/java/org/lowcoder/plugins/SmtpPlugin.java#L83C1-L91C66) that I realized that only SMARTTLS SMTP servers can be configured.
After switching the datasource settings to port 587, it now works without issues.

Describe the solution you'd like
Either:

• Explain clearly in the GUI that only SMARTTLS servers are allowed

Or:

• Modify the plugin code to allow either SMARTTLS / TLS (/ maybe also plain?) servers
• And adjust the GUI to reflect this option

Describe alternatives you've considered
None, as my SMTP server luckily offers SMARTTLS

Additional context
None