Add sidebarSearchForm

[osenan]

Include a component similar to shinydashboard::sidebarSearchForm using shiny.semantic components

The sidebarSearchForm is a ui component that queries a search and is placed on the sidebar.
https://github.com/rstudio/shinydashboard/blob/main/R/dashboardSidebar.R#L188
It contains as argument a textId for the id of the input text, a buttonId for the created icon button to be reactive in the server, a label for the label of the input and an icon for selecting the icon that will act as a button.

Here an example app of the sidebarSearchForm

library(shiny)
library(shinydashboard)

header <- dashboardHeader()
sidebar <- dashboardSidebar(
  sidebarSearchForm(label = "Enter a number", "searchText", "searchButton"),
  sidebarMenu(
    # Setting id makes input$tabs give the tabName of currently-selected tab
    id = "tabs",
    menuItem("Dashboard", tabName = "dashboard", icon = icon("dashboard")),
    menuItem("Widgets", icon = icon("th"), tabName = "widgets", badgeLabel = "new",
             badgeColor = "green"),
    menuItem("Charts", icon = icon("calendar"),
      menuSubItem("Sub-item 1", tabName = "subitem1"),
      menuSubItem("Sub-item 2", tabName = "subitem2")
    )
  )
)
body <- dashboardBody(
  tabItems(
    tabItem("dashboard",
      div(p("Dashboard tab content"))
    ),
    tabItem("widgets",
      "Widgets tab content"
    ),
    tabItem("subitem1",
      "Sub-item 1 tab content"
    ),
    tabItem("subitem2",
      "Sub-item 2 tab content"
    )
  )
)
shinyApp(
  ui = dashboardPage(header, sidebar, body),
  server = function(input, output) { }
)

In our implementation, we could create a function that acts as a wrapper of [shiny semantic search functions](https://github.com/rstudio/shinydashboard/blob/main/R/dashboardSidebar.R#L188) and include - if needed - format to display it nicely on the sidebar. New arguments can be created appart from the current ones avaiable in shiny.dashboard.