fix: add output-dir to cache, use it if found W-17919149

[WillieRuemmele]

What does this PR do?

adds output directory to cache, will read and use it on resume

What issues does this PR fix or reference?

@W-17919149@

[cristiand391]

QA notes:

🟡 resume respects --output-dir from async run
It does respect it but always writes results in human result (async run requested them in tap format)

➜  plugin-agent git:(wr/cacheOutputDir) sf agent test run --api-name Local_Info_Agent_Test --output-dir res --result-format tap
 ›   Warning: @salesforce/plugin-agent is a linked ESM module and cannot be
 ›   auto-transpiled. Existing compiled source will be used instead.Warning: This command is currently in beta. Any aspect of this command can change without advanced notice. Don't use beta commands in your scripts.

 ───── Agent Test Run: Local_Info_Agent_Test ─────

 ✔ Starting Tests 1.10s
 ◼ Polling for Test Results

 Job ID: 4KBed000000bytFGAQ
 Elapsed Time: 1.13s

Run sf agent test resume --job-id 4KBed000000bytFGAQ to resuming watching this test.
➜  plugin-agent git:(wr/cacheOutputDir) sf agent test resume --job-id 4KBed000000bytFGAQ
 ›   Warning: @salesforce/plugin-agent is a linked ESM module and cannot be
 ›   auto-transpiled. Existing compiled source will be used instead.
Warning: This command is currently in beta. Any aspect of this command can change without advanced notice. Don't use beta commands in your scripts.

 ───── Agent Test Run: Local_Info_Agent_Test ─────

 ✔ Starting Tests 22ms
 ✔ Polling for Test Results 1.58s
   ▸ Status: COMPLETED
   ▸ Completed Test Cases: 2/2
   ▸ Passing Test Cases: 0
   ▸ Failing Test Cases: 2

 Job ID: 4KBed000000bytFGAQ
 Elapsed Time: 1.63s

Created human-readable file at res/test-result-4KBed000000bytFGAQ.txt