refactor: use reference type in DataFrame

[bsbds]

Depends-On: #680

Please briefly answer these questions:

• what problem are you trying to solve? (or if there's no problem, what's the motivation for this change?)

• what changes does this pull request make?

• are there any non-obvious implications of these changes? (does it break compatibility with previous versions, etc)

[mergify[bot]]

@bsbds Convert your pr to draft since CI failed

[mergify[bot]]

@bsbds Convert your pr to draft since CI failed

[mergify[bot]]

@bsbds Convert your pr to draft since CI failed

[mergify[bot]]

@bsbds Convert your pr to draft since CI failed

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 83.08157% with 56 lines in your changes are missing coverage. Please review.

Project coverage is 75.43%. Comparing base (e35b35a) to head (0395358). Report is 28 commits behind head on master.

Files	Patch %	Lines
crates/curp/src/server/storage/wal/segment.rs	70.58%	7 Missing and 13 partials :warning:
crates/curp/src/server/storage/wal/remover.rs	86.46%	7 Missing and 11 partials :warning:
crates/curp/src/server/storage/wal/pipeline.rs	84.50%	8 Missing and 3 partials :warning:
crates/curp/src/server/storage/wal/codec.rs	88.13%	5 Missing and 2 partials :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #740      +/-   ##
==========================================
- Coverage   75.55%   75.43%   -0.12%     
==========================================
  Files         180      183       +3     
  Lines       26938    27039     +101     
  Branches    26938    27039     +101     
==========================================
+ Hits        20353    20398      +45     
- Misses       5366     5376      +10     
- Partials     1219     1265      +46     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.