Deleting multiple layers issue #317

[Gurpreetsingh9465]

This is a PR regarding issue #317

1. multiple layer selection
2. deletion
3. confirmation
4. improved the logic of tracking nextlayer
5. making sure the the default select layer method does not conflict with this

[Gurpreetsingh9465]

Right click selects the layer

[yashdusing]

A few issues I've encountered :

1. If side panel is enabled, selection is not possible.
2. Selection of layer could be highlighted using some different css techniques. Something like blurring would be good imo. First discuss with @Ram81 about the css.
3. All caps for the deletion message. Again, consult @Ram81 about this
4. After deleting a number of layers, the last remaining layer does not track next layer i.e. layer addition does not append layer to last layer

[Gurpreetsingh9465]

Right now the code is in a way that If sidepane is enabled then you can't select or deselect layers further and the the sidepanel layer is deselected.

[Gurpreetsingh9465]

The new layer is appending I guess you can see it on the .gif as well can you send me the console output

[yashdusing]

Sorry, I was a little busy. Here you go.

[yashdusing]

Steps to recreate :

1. Load ZFnet
2. Select random layers from the middle and then delete these layers
3. Then select one of the 2 remaining sets and delete it.
4. Now try adding layers

[yashdusing]

Also, please do something about the css. It's hard to keep track of the selected layers

[Gurpreetsingh9465]

updated the css

[Ram81]

@Gurpreetsingh9465 can you please remove the changes for adding Vnect to model zoo from this PR. Don't add redundant code

[Gurpreetsingh9465]

Changes done.

[gautamjajoo]

Please remove the image of vnect model.