refactor(ziputil): remove non-zipping related utilities out of ZipUtil (aws#6830)

## Problem
`ZipUtil` contains a mix of different utilities from working with
workspaces, to computing git diffs. These are all used in zipping the
project, but inherently have no connection to it.

Larger problem is that `ZipUtil` is highly coupled to agent
implementations and is difficult to generalize. Moving out non-zipping
noise will help.

## Solution
- Move these utils to more appropriate locations. 
- Move the `GitDiff` utilities out of the `ZipUtil` class. These
functions have no test coverage and are therefore unsafe to export or
move to their own file in its current state.

## Future Work
Refactor to avoid references to scope and use case. 

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: Hweinstock

packages/core/src/codewhisperer/commands/startSecurityScan.ts

@@ -50,6 +50,7 @@ import {
 import { SecurityIssueTreeViewProvider } from '../service/securityIssueTreeViewProvider'
 import { ChatSessionManager } from '../../amazonqScan/chat/storages/chatSession'
 import { TelemetryHelper } from '../util/telemetryHelper'
+import { getWorkspacePaths } from '../../shared/utilities/workspaceUtils'
 
 const localize = nls.loadMessageBundle()
 export const stopScanButton = localize('aws.codewhisperer.stopscan', 'Stop Scan')
@@ -156,7 +157,7 @@ export async function startSecurityScan(
             })
         }
         const zipMetadata = await zipUtil.generateZip(editor?.document.uri, scope)
-        const projectPaths = zipUtil.getProjectPaths()
+        const projectPaths = getWorkspacePaths()
 
         const contextTruncationStartTime = performance.now()
         codeScanTelemetryEntry.contextTruncationDuration = performance.now() - contextTruncationStartTime

packages/core/src/codewhisperer/commands/startTestGeneration.ts

@@ -21,6 +21,7 @@ import { ChildProcess, spawn } from 'child_process' // eslint-disable-line no-re
 import { BuildStatus } from '../../amazonqTest/chat/session/session'
 import { fs } from '../../shared/fs/fs'
 import { Range } from '../client/codewhispereruserclient'
+import { getWorkspaceForFile } from '../../shared/utilities/workspaceUtils'
 
 // eslint-disable-next-line unicorn/no-null
 let spawnResult: ChildProcess | null = null
@@ -48,7 +49,7 @@ export async function startTestGenerationProcess(
 
         const zipUtil = new ZipUtil()
         if (initialExecution) {
-            const projectPath = zipUtil.getProjectPath(filePath) ?? ''
+            const projectPath = getWorkspaceForFile(filePath) ?? ''
             const relativeTargetPath = path.relative(projectPath, filePath)
             session.listOfTestGenerationJobId = []
             session.shortAnswer = undefined

packages/core/src/codewhisperer/models/constants.ts

@@ -926,3 +926,7 @@ export const testGenExcludePatterns = [
     '**/*.deb',
     '**/*.model',
 ]
+
+export const isFileAnalysisScope = (scope: CodeAnalysisScope) => {
+    return scope === CodeAnalysisScope.FILE_AUTO || scope === CodeAnalysisScope.FILE_ON_DEMAND
+}