Add searchable character pattern for Name and Description

[mdgrs-mei]

This PR adds NameSearchablePattern and DescriptionSearchablePattern properties to SelectorEntry. If specified, Only characters that are matched by the regex pattern will be searchable.

Example1: The second word split by space is searchable

$pattern = [Regex]::new('(?<=^\S*\s).*?(?=\s|$)')
'aaa bbb aaa', 'bbb aaa bbb' | ForEach-Object {
    $entry = [PowerShellRun.SelectorEntry]::new()
    $entry.Name = $_
    $entry.NameSearchablePattern = $pattern
    $entry
} | Invoke-PSRunSelectorCustom

Example2: All words inside [] are searchable

$pattern = [Regex]::new('(?<=\[).*?(?=\])')
'aaa [bbb] [ccc]', '[aaa] bbb ccc' | ForEach-Object {
    $entry = [PowerShellRun.SelectorEntry]::new()
    $entry.Name = $_
    $entry.NameSearchablePattern = $pattern
    $entry
} | Invoke-PSRunSelectorCustom

Example3: Method or Property names are searchable

$pattern = [Regex]::new('(?<=^\S*\s).*?(?=\s|\(|{|$)')
$members = [Regex] | Get-Member
$members | ForEach-Object {
    $entry = [PowerShellRun.SelectorEntry]::new()
    $entry.Name = $_.Definition
    $entry.NameSearchablePattern = $pattern
    $entry
} | Invoke-PSRunSelectorCustom