Expand GitHub issue templates with playback and TV-focus forms

[oxyroid]

Motivation

• Reduce empty/low-quality issues by disabling blank issues and giving links to Telegram, README, and latest release.
• Improve bug triage by collecting variant, install source, device/Android details, problem category, playlist context, and sanitized logs.
• Provide specialized forms for playback and Android TV focus problems to gather protocol/codec, ExoPlayer behavior, network, and DPad path details.
• Improve feature requests with user scenarios, alternatives, platform scope, and compatibility impact to evaluate change risk.

Description

• Add .github/ISSUE_TEMPLATE/config.yml to disable blank issues and surface contact links (Telegram, README, latest release).
• Update bug_report.md to include app variant, installation source, app version/commit, device and Android environment, problem type checklist, playlist/provider context, and clearer log/screenshot guidance.
• Add playback_issue.md to collect stream URL type, codecs, external player comparison, network environment, Media3/ExoPlayer symptoms, reproduction steps, and sanitized logs.
• Add tv_focus_issue.md to collect TV device info, affected screen/entry path, exact remote/DPad button path, initial-focus expectations, back/confirm problems, and screenshot/recording attachments.
• Extend feature_request.md with user scenario, alternatives/workarounds, platform scope, and explicit compatibility-impact fields, and remove trailing whitespace from templates.

Testing

• Ran git diff --check which initially reported trailing whitespace issues in the edited templates.
• Fixed whitespace with perl -pi -e 's/[ \t]+$//' .github/ISSUE_TEMPLATE/*.md .github/ISSUE_TEMPLATE/config.yml and re-ran git diff --check, which passed with no remaining check failures.
• Verified the new and updated template files are present with nl -ba .github/ISSUE_TEMPLATE/*.

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Codex Task