Redo tempo-cli with basic command structure and improvements

[mdisibio]

What this PR does:
Redo of tempo-cli to have basic command structure for easier maintenance and new commands. Existing three commands now look like:

• tempo-cli list block <tenant-id> <block-id>
• tempo-cli list blocks <tenant-id>
• tempo-cli query <trace-id>

Notable changes:

• Using kong library, provides help (-h, --help) and discoverability at each level (./tempo-cli -h, list -h, list blocks -h)
• Added universal --config-file (-c) parameter to load backend settings from existing tempo yaml. --backend, etc existing parameters can still be used and override config values if both are used.
• Updated behavior of list block/blocks commands to put expensive operations behind additional flags: By default only meta is loaded. list blocks --load-index to check index for dupes and record counts, list block --check-dupes to load block and check for duplicate trace ids.

Which issue(s) this PR fixes:
Fixes #281

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[joe-elliott]

Welcome improvement in both code organization and tempo-cli ux.

The current main readme.md now contains some out of date info on tempo-cli. What do you think about adding updated info to the ./docs folder and just linking to it from the main readme?

[mdisibio]

Welcome improvement in both code organization and tempo-cli ux.

The current main readme.md now contains some out of date info on tempo-cli. What do you think about adding updated info to the ./docs folder and just linking to it from the main readme?

Agree. Added CLI section to docs that covers commands, options, etc, and updated readme to link to it.

[annanay25]

Fantastic work, thank you @mdisibio! Can you please also add a CHANGELOG entry and then we can merge this!

[achatterjee-grafana]

Doc content looks good. Added some copy-edit suggestions.