TFC: Support for test run

[radeksimko]

Background

As part of #1590 we introduced support for structured log output, where all kinds of actions (planned_change, resource_drift, outputs, diagnostics) are represented in the UI (tree view):

vscode-terraform/src/providers/tfc/planProvider.ts

Lines 116 to 172 in 284c5fe

	const logLine: LogLine = JSON.parse(line);
	if (logLine.type === 'planned_change' && logLine.change) {
	if (!planLog.plannedChanges) {
	planLog.plannedChanges = [];
	}
	planLog.plannedChanges.push(logLine.change);
	continue;
	}
	if (logLine.type === 'resource_drift' && logLine.change) {
	if (!planLog.driftChanges) {
	planLog.driftChanges = [];
	}
	if (!planLog.driftSummary) {
	planLog.driftSummary = {
	changed: 0,
	deleted: 0,
	};
	}
	planLog.driftChanges.push(logLine.change);
	if (logLine.change.action === 'update') {
	planLog.driftSummary.changed += 1;
	}
	if (logLine.change.action === 'delete') {
	planLog.driftSummary.deleted += 1;
	}
	continue;
	}
	if (logLine.type === 'change_summary' && logLine.changes) {
	planLog.changeSummary = logLine.changes;
	continue;
	}
	if (logLine.type === 'outputs' && logLine.outputs) {
	planLog.outputs = logLine.outputs;
	continue;
	}
	if (logLine.type === 'diagnostic' && logLine.diagnostic) {
	if (!planLog.diagnostics) {
	planLog.diagnostics = [];
	}
	if (!planLog.diagnosticSummary) {
	planLog.diagnosticSummary = {
	errorCount: 0,
	warningCount: 0,
	};
	}
	planLog.diagnostics.push(logLine.diagnostic);
	if (logLine.diagnostic.severity === 'warning') {
	planLog.diagnosticSummary.warningCount += 1;
	}
	if (logLine.diagnostic.severity === 'error') {
	planLog.diagnosticSummary.errorCount += 1;
	}
	continue;
	}
	// TODO: logLine.type=test_*

In the PR, we decided to omit support for test actions as there's many of them and it would therefore involved non-trivial amount of effort to add the support and understand the context for each action.

Test actions

• test_abstract
• test_file
• test_run
• test_cleanup
• test_summary
• test_plan
• test_state
• test_interrupt

Proposal

• Read up on the meaning of each test action to understand the meaning/context: https://developer.hashicorp.com/terraform/internals/machine-readable-ui
• Add support for any test_* action which is considered meaningful per ^