fix: grep escaped chars and empty results

[RomneyDa]

Description

• Adds handling for improperly escaped chars in grep patterns post JSON-parsing, along with explanations for the model in case this fails
• Makes truncation warning context items for various tools less ugly by removing unnecessary description and shortening name
• Bumps grep token limit from ~1000 to ~1500
• Adds meaningful no-result context items for glob and grep queries that return zero results

CON-3953
CON-3497

[github-actions]

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[cubic-dev-ai]

2 issues found across 13 files

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