v1.2: Add new `IS NULL` and `IS EMPTY` filter operators

[guimachiavelli]

v1.2 introduces two new filter operators, IS NULL and IS EMPTY.

IS NULL matches fields that exist but have an explicit null value:

{
  "name": null
}

IS EMPTY matches fields that exist but have an empty value, including strings, objects, and arrays:

{
  "name": "",
  "reviews": [],
  "locations": {}
}

Both operators can be used together with NOT: IS NOT EMPTY, NOT [attribute] IS EMPTY, IS NOT NULL, NOT [attribute] IS NULL.

Tasks

• Update /learn/advanced/filtering.mdx

References

• spec: Filter operators - IS NULL and IS EMPTY filter operators specifications#232
• issues: IS NULL filter operator meilisearch#3615, IS EMPTY filter operator meilisearch#3614
• SME: @Kerollmops

[maryamsulemani97]

fixed in #2416