New processors to expand ingest node's capabilities

[martijnvg]

This meta issue is keeping track of the new processor that should be added to ingest in the short to mid term. The addition of these new processors will make ingest more versatile and therefor easier to be used for different purposes.

New processors planned for development:

• Hash processor. See [ingest] Re-introduce the Hash Processor with consistent keys across all nodes #34085 (in progress).
• Time duration processor. See Ingest node (time) duration processor #39857 (in progress).
• CSV processor. CSV processor #49113
• IP processor. See Ingest node: IP Address Processor #38064 (in progress).
• Language detection processor. See Add a language-detection processor to Ingest Node #29094
• Time processor. See Ingest node time period processor #40615
• Unit conversion processor. See Add unit conversion ingest node processor #31737
• Expose ML's domainSplit() function as processor. See [Ingest] Expose domainSplit() in ingest script processor and possibly aggregations #36359 UPDATE: The registered domain processor was added in Registered domain processor #67611
• Percolate processor. (more details follow)

[elasticmachine]

Pinging @elastic/es-core-features (:Core/Features/Ingest)