Fixed heatplot method not returning base64 encoded image

[Tom-Kingstone]

NOTE: Depends on

Issues addressed by this PR

Closes #174

save_path variable now includes a check for empty string including None

Test files

LBT_Plots.zip
change the save directory (preset as C:/github/0_temp/temp.png) to an empty string or remove the panel entirely, and run the HeatPlotCommand

Changelog

Additional comments

[Tom-Kingstone]

@BHoMBot check core
@BHoMBot check compliance

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check core
• check code-compliance
• check documentation-compliance
• check project-compliance
• check branch-compliance
• check dataset-compliance
• check copyright-compliance

[Tom-Kingstone]

@BHoMBot check versioning

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check versioning

[Tom-Kingstone]

@BHoMBot check required

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check code-compliance
• check documentation-compliance
• check project-compliance
• check core
• check null-handling
• check serialisation
• check versioning
• check installer

[jamesramsden-bh]

Proposed change works well.

[Tom-Kingstone]

@BHoMBot check unit-tests

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check unit-tests

[Tom-Kingstone]

@BHoMBot check ready-to-merge

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check ready-to-merge