Add extra type for manifest validation

[nmuesch]

What does this PR do?

Add crawler to the list of types that a manifest can have.

Motivation

Some partner based integrations don't utilize the Agent structure and are instead more crawler based. This allows us to properly categorize those.

Additional Notes

The fix parameter will no longer fix the type here. Since there are multiple allowed types you can't determine which it should be.

Review checklist (to be filled by reviewers)

• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached
• Feature or bugfix must have tests
• Git history must be clean
• If PR adds a configuration option, it must be added to the configuration file.

[codecov]

Codecov Report

Merging #3662 into master will decrease coverage by 8.35%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3662      +/-   ##
==========================================
- Coverage   86.11%   77.75%   -8.36%     
==========================================
  Files         725       31     -694     
  Lines       37483     1043   -36440     
  Branches     4498       93    -4405     
==========================================
- Hits        32277      811   -31466     
+ Misses       3967      202    -3765     
+ Partials     1239       30    -1209