[LLVM][MLIR] Move LSP server support library from MLIR into LLVM (#155572)

This PR moves the generic Language Server Protocol (LSP) server support
code that was copied from clangd into MLIR, into the LLVM tree so it can
be reused by multiple subprojects.

Centralizing the generic LSP support in LLVM lowers the barrier to
building new LSP servers across the LLVM ecosystem and avoids each
subproject maintaining its own copy.

The code originated in clangd and was copied into MLIR for its LSP
server. MLIR had this code seperate to be reused by all of their LSP
server. This PR relocates the MLIR copy into LLVM as a shared component
into `LLVM/Support`. If this is not a suitable place, please suggest a
better one.

A follow up to this move could be deduplication with the original clangd
implementation and converge on a single shared LSP support library used
by clangd, MLIR, and future servers.

### What changes
* `mlir/include/mlir/Tools/lsp-server-support/{Logging, Protocol,
Transport}.h` moved to `llvm/include/llvm/Support/LSP`
* `mlir/lib/Tools/lsp-server-support/{Logging, Protocol, Transport}.cpp`
moved to `llvm/lib/Support/LSP`

and their namespace was changed from `mlir` to `llvm`

I ran clang-tidy --fix and clang-format on the whole moved files (last
two commits), as they are basically new files and should hold up to the
code style used by LLVM.

MLIR LSP servers where updated to include these files from their new
location and account for the namespace change.

This PR is made as part of the LLVM IR LSP project
([RFC](https://discourse.llvm.org/t/rfc-ir-visualization-with-vs-code-extension-using-an-lsp-server/87773))

0 files changed, 0 insertions, 0 deletions