use vscode files API instead

[0mkara]

we have been using native fs in multiple places like -

We should be using vscode file system API instead whereever possible.

[Krish-bhardwaj]

To migrate from node fs module to vscode File System API we will have to change following things
Documentation

1. Structure change
   • initially we are using the normal file system used in os for eg . Path type : C:\Users\...\hardhat\contracts\greeter.sol would change to vscode.URI type file://Users\...\hardhat\contracts\greeter.sol so initiall we woild want to change path type to vscode.URI
   • All the function that are available in fs module are not exactly available in vscode File System API thus we would have to rewrite the function where ever there is a use of fs module in ethcode , but as per my observation we have all the required api for our current need
   • We can observe changes in code base by following examples
     • if we read a file using normal fs module it would work like this

                     const getDeployedInputs: any = (context: vscode.ExtensionContext) => {
                       try {
                         const contract = context.workspaceState.get(
                           'contract'
                         ) as CompiledJSONOutput
                         const fullPath = getDeployedFullPath(contract)
                         const inputs = fs.readFileSync(fullPath).toString()
                         return JSON.parse(inputs)
                       } catch (e) {
                         return undefined
                       }
                     }

     • if we read a file using vscode File System API it would work like this

       const getFunctionInputFile: any = async (
       context: ExtensionContext,
       name: string
     ): Promise<object | undefined> => {
       try {
         const contracts = context.workspaceState.get('contracts') as Record<string, CompiledJSONOutput>
         if (contracts === undefined || Object.keys(contracts).length === 0) return
     
         const contract = Object.values(contracts).find(contract => contract.name === name)
         if (contract != null) {
           const link = getFunctionInputFullPath(contract)
           const linkchnage = link.replace(/\\/g, '/')
           const parsedUrl = new URL(linkchnage)
           const fileUrl: vscode.Uri = vscode.Uri.parse(`file://${parsedUrl.pathname}`)
           const contents: Uint8Array = await vscode.workspace.fs.readFile(fileUrl)
           const decoder = new TextDecoder()
           const jsonString = decoder.decode(contents)
           const json = JSON.parse(jsonString)
           return json
         }
       } catch (error) {
         console.log(error)
       }
     } 

2. Output change
   • We are not sure that how much role does fs module play in terms of performance and how better is it going to be if we use vscode File System API
   • Right now ethcode extension is working fine with this fs module
   • If we plan to migrate or standardise vscode File System API for file related operation in ethcode we should make sure that further whatever development are should be made in vscode File System API and gradually migrate previous code base to the same