[FEATURE] Support custom email banner/image

[joshuali925]

Is your feature request related to a problem?

Currently the email banner is hard coded

reporting-cli/src/email-helpers.js

Lines 46 to 53 in 51f8869

	transporter.use("compile", hbs({
	viewEngine: {
	partialsDir: path.join(__dirname, './views/'),
	defaultLayout: ""
	},
	viewPath: path.join(__dirname, './views/'),
	extName: ".hbs"
	}));

reporting-cli/src/email-helpers.js

Lines 100 to 109 in 51f8869

	{
	filename: emailbody,
	path: emailbody,
	cid: 'email_body'
	},
	{
	filename: 'opensearch_logo_darkmode.png',
	path: path.join(__dirname, './views/opensearch_logo_darkmode.png'),
	cid: 'opensearch_logo_darkmode'
	},

What solution would you like?

It would be useful if reporting-cli supports a way to config them.

What alternatives have you considered?

A clear and concise description of any alternative solutions or features you've considered.

Do you have any additional context?

Add any other context or screenshots about the feature request here.

[Jerakin]

I would love the banner image to be customizable (or removable), I would want a way to only send the image really.

The banner (and accompanying text) is huge, the (combined) height is about 500px which combined with the UI of the email software means that the actual important content starts maybe halfway down the screen.