Fix recipe generation and loading

[therazix]

This PR addresses the following issues in the recipe feature:

• added missing to_spec/to_minimal_spec methods to the ReportPortal plugin.
• recipe loading now works even when the current working directory does not contain an fmf tree, by creating a fake tree during loading.

Blocking: https://gitlab.cee.redhat.com/fvagner/tmt-recipe-tool/-/merge_requests/1

Pull Request Checklist

• implement the feature

[gemini-code-assist]

Code Review

This pull request transitions the recipe system to use absolute paths for results and refactors the RecipeManager to handle fmf tree creation internally. It also adds custom serialization for ReportPortal report data to ensure correct formatting of log limits and patterns. A suggestion was made to remove a redundant tree check in tmt/base/core.py to support recipe loading in standalone environments where a tree might not yet exist.

[tcornell-bus]

I tried to verify the fix by doing a basic tmt run via container.

Then I moved into a blank directory with no fmf tree and tried to run with the recipe file:
(tmt version: 1.71.0)

tcornell ~/tmp $ tmt run -vvv --recipe /var/tmp/tmt/run-063/recipe.yaml

No metadata found in the '.' directory. Use 'tmt init' to get started.

The exception was caused by 1 earlier exceptions

Cause number 1:

    Unable to find tree root for '/home/tcornell/tmp'.

(PR)

(dev) tcornell ~/tmp $  tmt run -vvv --recipe /var/tmp/tmt/run-063/recipe.yaml

[...]

    execute
        queued execute tasks
            #1: default-0 on default-0
        
        execute task #1: default-0 on default-0
        how: tmt
        order: 50
        ignore-duration: false
        exit-first: false
            test: Concise summary describing what the test does
                duration deadline: 300 seconds, at 16:23:03 2026-04-20 UTC
                cmd: ./test.sh
                stdout: ./tmt-test-wrapper-inner.sh-smoke-1-default-0-default-0: line 1: ./test.sh: No such file or directory
                00:00:00 errr /smoke (on default-0) [1/1]
                    Note: beakerlib: TestResults FileError

    
        summary: 1 test executed

Looks like it made the fake tree, but the tree does not have the supporting test files.
When I execute the same command in the original fmf root directory, it runs fine.

Am I reproducing this correctly?

[tcornell-bus]

Not sure if this PR is supposed to fix this or not, but I did a tmt run with report --how reportportal --project <my_project> and it made the recipe.yaml file with the key/values in the to_spec()\to_minimal_spec() functions. Then I tried loading that same recipe file (in the fmf root directory), and I got an exception:

/plans/all
summary: Run all tests

plan failed.

The exception was caused by 1 earlier exceptions

Cause number 1:

    cannot represent an object: {1: '<some-hash>'}

Where {1: '<some-hash>'} is the reportportal test-uuids value.