Don't panic when creating FileBackedHistory with usize::MAX capacity

[nibon7]

This pr makes FileBackedHistory::new() return Result<FileBackedHistory> and it will not panic when passing usize::MAX as capacity.

When setting $env.config.history.max_size = -1, nushell returns an error instead of panicking.

❯ ./target/debug/nu
Error:   × error within history: History capacity too large to be addressed safely

[codecov]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

Comparison is base (9ca229d) 47.59% compared to head (eb2303b) 49.40%.
Report is 2 commits behind head on main.

❗ Current head eb2303b differs from pull request most recent head 625d7ba. Consider uploading reports for the commit 625d7ba to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #701      +/-   ##
==========================================
+ Coverage   47.59%   49.40%   +1.80%     
==========================================
  Files          47       46       -1     
  Lines        9312     8006    -1306     
==========================================
- Hits         4432     3955     -477     
+ Misses       4880     4051     -829     

Files	Coverage Δ
src/history/base.rs	84.30% <100.00%> (+0.35%)	⬆️
src/history/file_backed.rs	82.70% <94.11%> (+0.68%)	⬆️
src/result.rs	0.00% <0.00%> (ø)

... and 20 files with indirect coverage changes