bf: ARSN-398 DelimiterMaster: fix when gap building is disabled

[jonathan-gramain]

• Fix the situation where gap building is disabled by _saveBuildingGap() but we attempted to reset the building gap state anyway.

• Introduce a new state 'Expired' that can be differentiated from 'Disabled': it makes getGapBuildingValidityPeriodMs() return 0 instead of 'null' to hint the listing backend that it should trigger a new listing.

[bert-e]

Hello jonathan-gramain,

My role is to assist you with the merge of this
pull request. Please type @bert-e help to get information
on this process, or consult the user documentation.

Status report is not available.

[bert-e]

Request integration branches

Waiting for integration branch creation to be requested by the user.

To request integration branches, please comment on this pull request with the following command:

/create_integration_branches

Alternatively, the /approve and /create_pull_requests commands will automatically
create the integration branches.

[jonathan-gramain]

/approve

[bert-e]

Conflict

A conflict has been raised during the creation of
integration branch w/8.1/bugfix/ARSN-398-doNotRefreshGapBuildingIfDisabled with contents from bugfix/ARSN-398-doNotRefreshGapBuildingIfDisabled
and development/8.1.

I have not created the integration branch.

Here are the steps to resolve this conflict:

 $ git fetch
 $ git checkout -B w/8.1/bugfix/ARSN-398-doNotRefreshGapBuildingIfDisabled origin/development/8.1
 $ git merge origin/bugfix/ARSN-398-doNotRefreshGapBuildingIfDisabled
 $ # <intense conflict resolution>
 $ git commit
 $ git push -u origin w/8.1/bugfix/ARSN-398-doNotRefreshGapBuildingIfDisabled

The following options are set: approve

[bert-e]

In the queue

The changeset has received all authorizations and has been added to the
relevant queue(s). The queue(s) will be merged in the target development
branch(es) as soon as builds have passed.

The changeset will be merged in:

• ✔️ development/7.70

• ✔️ development/8.1

The following branches will NOT be impacted:

• development/6.4
• development/7.10
• development/7.4

There is no action required on your side. You will be notified here once
the changeset has been merged. In the unlikely event that the changeset
fails permanently on the queue, a member of the admin team will
contact you to help resolve the matter.

IMPORTANT

Please do not attempt to modify this pull request.

• Any commit you add on the source branch will trigger a new cycle after the
  current queue is merged.
• Any commit you add on one of the integration branches will be lost.

If you need this pull request to be removed from the queue, please contact a
member of the admin team now.

The following options are set: approve

[bert-e]

I have successfully merged the changeset of this pull request
into targetted development branches:

• ✔️ development/7.70

• ✔️ development/8.1

The following branches have NOT changed:

• development/6.4
• development/7.10
• development/7.4

Please check the status of the associated issue ARSN-398.

Goodbye jonathan-gramain.