Added functionality to send email using SMTP

[AmanDevelops]

Issue Referenced

closes #45

Describe the Changes

Change 1: src/assistant.py

• Implemented a query processor to extract the recipient's email address, subject, and body from the user query.

Change 2: src/commands.py

• Implementation of send email functionality

Type of Change

• New feature (non-breaking change which adds functionality)

Additional Setup Requirements

• user needs to provide additional details to src/email_config.json file and set SMTP password in environmental variable "DESKTOP_ASSISTANT_SMTP_PWD"

Necessary Conditions

• I have commented on my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• The changes do not involve any Private data leak/reveal.
• Secrets, if any, are kept hidden via an environment file, whose structure has been explained via documentation.

Please make sure to check the following milestones before submitting the bug report!

[AmanDevelops]

[AmanDevelops]

[vihar-s1]

@AmanDevelops can you specify how did you setup the server for testing the email feature ?