fix: clears gsa cache when new file is opened on connector (SPEC-517)

[dtnaughton]

Description & motivation

• If a commit is received into GSA in one instance of SpeckleGSA, and then the user opens a new file and receives a different commit, previously data from the first commit would be kept in the cache and therefore written into the new file. This can put unintended data into the model.

Changes:

• On selecting 'New File' on SpeckleGSA connector, the gsa cache is cleared of all records.

To-do before merge:

N/A

Screenshots:

N/A

Validation of changes:

• Manual test receiving two different commits into different GSA models created using the 'New File' SpeckleGSA feature.

Checklist:

• My pull request follows the guidelines in the Contributing guide?
• My pull request does not duplicate any other open Pull Requests for the same update/change?
• My commits are related to the pull request and do not amend unrelated code or documentation.
• My code follows a similar style to existing code.
• I have added appropriate tests.
• I have updated or added relevant documentation.

References