feat(datapoints-graph): added export to csv

[janhommes]

Proposed changes

Adds a CSV export to the datapoints view

• new button for export
• new modal for defining the filename and separator of the export
• new configuration to export

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

#18

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[jdre-c8y]

Suggested change

	"jest-preset-angular": "^12.2.0",
	"jest-preset-angular": "^12.2.0",
	"@types/file-saver": "^2.0.7",

[jdre-c8y]

Suggested change

	this.isLoading = true;
	import('file-saver').then((fileSaver) => {
	for (const series of this.csvData) {
	const dataSet = series.data
	.map((value: string[]) => value.join(this.form.separator))
	.join('\n');
	const blob = new Blob([dataSet], { type: 'text/csv;charset=utf-8' });
	fileSaver.default.saveAs(blob, `${this.form.fileName}${series.id}.csv`);
	}
	this.isLoading = false;
	this.bsModalRef.hide();
	});
	import { saveAs } from 'file-saver';
	...
	this.isLoading = true;
	for (const series of this.csvData) {
	const dataSet = series.data
	.map((value: string[]) => value.join(this.form.separator))
	.join('\n');
	const blob = new Blob([dataSet], { type: 'text/csv;charset=utf-8' });
	saveAs(blob, `${this.form.fileName}${series.id}.csv`);
	}
	this.isLoading = false;
	this.bsModalRef.hide();

[jdre-c8y]

why using import in method (as inline method, in method)? package file-saver is rather lightweightm, does it need lazy loading? also, after adding types, it's usage is more predictable (e.g. I immediately know that it is synchronous, but I was not sure before)

[jdre-c8y]

also I found a little issue on chrome- when we try to download multiple files at once (our case- I try to download csv of two series in data points graph), chrome blocks it and it's easy to miss that second file download was blocked. not sure if it's possible to handle as it's browser limitation, but if there is- it's worth to make it more user friendly.