This commit adds support for renaming symbols in tsserver and with LSP tools, and for organising imports with tsserver. Completion results for symbols that can be imported are now suggested if enabled for tsserver completion done via ALE.
Each LSP connection now stores its configuration dictionary. It is
initially empty (`{}`) and is updated each time the LSP connection is
started. When a change is detected, the workspace/didChangeConfiguration
message is sent to the LSP servers with the updated configuration.
