Add benchmarks for xrootd and webdav

[camposandro]

Implements a simple testing suite to benchmark data access via XRootD and WebDAV. Closes #1344.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 3.48%. Comparing base (382d810) to head (ab09ada).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/lbench/dashboard/utils.py	0.00%	3 Missing ⚠️
src/lbench/dashboard/metrics/metric.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main     #14      +/-   ##
========================================
- Coverage   3.49%   3.48%   -0.01%     
========================================
  Files         26      26              
  Lines       1060    1062       +2     
========================================
  Hits          37      37              
- Misses      1023    1025       +2     

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[nevencaplar]

LGTM

[camposandro]

For reference, I ran some of the benchmarks from my local machine.

Open catalog and compute

Benchmark	http	aws	xrootd	webdav
Open catalog (metadata only)	5.11 s	1.91 s	4.84 s	5.17 s
Open catalog (ra/dec only)	5.53 s	1.69 s	4.85 s	5.40 s
Open + compute partition (all cols)	104.07 s	45.17 s	190.34 s	89.68 s
Open + compute partition (ra/dec only)	7.97 s	2.87 s	17.86 s	7.53 s
Open + cone search + magnitude filter	331.30 s	117.83 s	369.45 s	282.66 s

Self-crossmatching GAIA DR3

Benchmark	xrootd × http	xrootd × aws	webdav × http	webdav × aws
Crossmatch (all cols)	766.64 s	479.70 s	607.27 s	478.31 s
Crossmatch (ra/dec only)	57.60 s	40.82 s	39.00 s	28.60 s

Each benchmark ran a single iteration.