[docs] Add prune CFD explainers, how-tos, utilities

[lparisc]

Change Description

Resolves DEVREL-40 - Add documentation for prune CFD feature (already reviewed from shared document):

• Update context-free data explainer (to include pruning)
• Update eosio-blocklog utility (to include pruning)
• Add "how to prune context-free data" procedure.

Also up-ports the following dependent PRs to develop:

• PR [docs] Add explainers on CFD, eosio utilities, eosio-blocklog - 2.0 #9479
• PR [docs] Minor edits on CFD explainer and eosio-blocklog reference - 2.0 #9487

Related to:

• PR [docs] Add slices, trace log, clog format explainers to Trace API plugin #9506

Change Type

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• Documentation

• Stability bug fix

• Other

• Other - special case

Consensus Changes

• Consensus Changes

API Changes

• API Changes

Documentation Additions

• Documentation Additions