feat(chat): Add validate method to fsRead tool

[tsmithsz]

Problem

Need to add validate method to be used by the chatController

Solution

Add validate method to fsRead tool

Testing

 FsRead Tool
extensionHostProcess.js:178
    ✔ throws if path is empty
extensionHostProcess.js:178
    ✔ reads entire file
extensionHostProcess.js:178
    ✔ reads partial lines of a file
extensionHostProcess.js:178
    ✔ lists directory contents up to depth = 1
extensionHostProcess.js:178
    ✔ throws error if path does not exist
extensionHostProcess.js:178
    ✔ throws error if content exceeds 30KB
extensionHostProcess.js:178
    ✔ invalid line range
extensionHostProcess.js:178
    ✔ expands ~ path
extensionHostProcess.js:178
    ✔ resolves relative path
extensionHostProcess.js:178
  9 passing (64ms)

---

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[github-actions]

• This pull request implements a feat or fix, so it must include a changelog entry (unless the fix is for an unreleased feature). Review the changelog guidelines.
  • Note: beta or "experiment" features that have active users should announce fixes in the changelog.
  • If this is not a feature or fix, use an appropriate type from the title guidelines. For example, telemetry-only changes should use the telemetry type.

[justinmk3]

DId you look at the existing fs utils here? normalize(), resolvePath():

aws-toolkit-vscode/packages/core/src/shared/utilities/pathUtils.ts

Line 92 in ce01fa8

export function normalize(p: string): string {

[justinmk3]

There is also sanitizeFilename.