Log function script exception and error details

[AnatoliB]

Resolves #145 (see the last proposal).

For example, the following script:

$ErrorActionPreference = 'Stop'
function MyFunctionA { 'abc' | ConvertFrom-Json }
function MyFunctionB { MyFunctionA }
MyFunctionB

will produce a trace like this:

[9/16/2019 7:46:23 PM] EXCEPTION: ConvertFrom-Json : Conversion from JSON failed with error: Unexpected character encountered while parsing value: a. Path '', line 0, position 0.
[9/16/2019 7:46:23 PM] At D:\GitHub\AnatoliB\af-ps-errors\Error\run.ps1:8 char:13
[9/16/2019 7:46:23 PM] +     'abc' | ConvertFrom-Json
[9/16/2019 7:46:23 PM] +             ~~~~~~~~~~~~~~~~
[9/16/2019 7:46:23 PM] + CategoryInfo          : NotSpecified: (:) [ConvertFrom-Json], ArgumentException
[9/16/2019 7:46:23 PM] + FullyQualifiedErrorId : System.ArgumentException,Microsoft.PowerShell.Commands.ConvertFromJsonCommand
[9/16/2019 7:46:23 PM]
[9/16/2019 7:46:23 PM] Script stack trace:
[9/16/2019 7:46:23 PM]    at MyFunctionA, D:\GitHub\AnatoliB\af-ps-errors\Error\run.ps1: line 8
[9/16/2019 7:46:23 PM]    at MyFunctionB, D:\GitHub\AnatoliB\af-ps-errors\Error\run.ps1: line 12
[9/16/2019 7:46:23 PM]    at <ScriptBlock>, D:\GitHub\AnatoliB\af-ps-errors\Error\run.ps1: line 17
[9/16/2019 7:46:23 PM]
[9/16/2019 7:46:23 PM] System.ArgumentException: Conversion from JSON failed with error: Unexpected character encountered while parsing value: a. Path '', line 0, position 0.
[9/16/2019 7:46:23 PM]    at Microsoft.PowerShell.Commands.JsonObject.ConvertFromJson(String input, Boolean returnHashtable, Nullable`1 maxDepth, ErrorRecord& error)
[9/16/2019 7:46:23 PM]    at Microsoft.PowerShell.Commands.ConvertFromJsonCommand.ConvertFromJsonHelper(String input)
[9/16/2019 7:46:23 PM]    at Microsoft.PowerShell.Commands.ConvertFromJsonCommand.EndProcessing()
[9/16/2019 7:46:23 PM]    at System.Management.Automation.Cmdlet.DoEndProcessing()
[9/16/2019 7:46:23 PM]    at System.Management.Automation.CommandProcessorBase.Complete()
[9/16/2019 7:46:23 PM]
[9/16/2019 7:46:23 PM] Inner exception: Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: a. Path '', line 0, position 0.
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonTextReader.ParseValue()
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonTextReader.Read()
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonReader.ReadAndMoveToContent()
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonReader.ReadForType(JsonContract contract, Boolean hasConverter)
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonSerializer.Deserialize(JsonReader reader, Type objectType)
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
[9/16/2019 7:46:23 PM]    at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, JsonSerializerSettings settings)
[9/16/2019 7:46:23 PM]    at Microsoft.PowerShell.Commands.JsonObject.ConvertFromJson(String input, Boolean returnHashtable, Nullable`1 maxDepth, ErrorRecord& error)

[Francisco-Gamino]

A couple of minor comments. Other than that, LGTM.