fix tracing configuration issues

[yaahc]

Prior to this change the configuration options for tracing were controlled exclusively by the tracing_config function in ZebraApp. This resulted in it ignoring all configuration options other than --verbose and more recently ZEBRAD_LOG. Notably, this function is called before the ZebraConfig is ever loaded, so it is impossible to consider the config filter level when initializing the tracing component.

To fix this, we have the new ZebraApp::level fn take the command as input, so it can prioritize the settings correctly. Then we call this function in tracing_config when the Config is None, giving us an initial config, then we call it again in after_config when the Config has been loaded and use that to reload the filter. This change requires a breaking change in the Abscissa API to pass the command along with the config in after_config so they can both be referenced when setting the final level.

fixes #98
fixes #399

[yaahc]

Because this change requires a breaking change to the API of abscissa I'm going to take this opportunity to also fix the Tracing component in abscissa so that it takes a user provided subscriber instead of always setting up its own default subscriber, that way we can setup layers like tracing-error and tracing-flame.

[hdevalence]

@yaahc Just to confirm, the relevant changes to abscissa are here, correct:

iqlusioninc/abscissa@develop...yaahc:develop

[yaahc]

@yaahc Just to confirm, the relevant changes to abscissa are here, correct:

iqlusioninc/abscissa@develop...yaahc:develop

Yup, the last line in that diff is some cruft that snuck in from earlier messing with error handling stuff but the rest of it is all the relevant stuff.

[codecov]

Codecov Report

Merging #432 into main will decrease coverage by 0.40%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #432      +/-   ##
==========================================
- Coverage   53.90%   53.49%   -0.41%     
==========================================
  Files          68       68              
  Lines        3278     3303      +25     
==========================================
  Hits         1767     1767              
- Misses       1511     1536      +25     

Impacted Files	Coverage Δ
zebrad/src/application.rs	0.00% <0.00%> (ø)
zebrad/src/commands/config.rs	0.00% <0.00%> (ø)
zebrad/src/commands/start.rs	0.00% <0.00%> (ø)
zebrad/src/config.rs	0.00% <0.00%> (ø)
zebra-chain/src/keys/sapling.rs	85.30% <0.00%> (ø)

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[dconnolly]

🚚

[dconnolly]

If the upsteam is not expected to merge quickly, perhaps make an issue to track 'point to the inqlusion version when available'

[tony-iqlusion]

FYI, we'd be happy to merge these changes upstream. Please open a PR.

[yaahc]

I plan to but I figured if we're gonna make a breaking change we should be sure that all the breaking changes are done at once, still thinking about changes to error handling.