[server] remove request functorial interface

src/plugins/server/data.ml

src/plugins/server/data.mli

src/plugins/server/kernel_ast.ml

src/plugins/server/kernel_ast.mli

src/plugins/server/kernel_fc.ml

src/plugins/server/kernel_fc.mli

src/plugins/server/kernel_project.ml

src/plugins/server/kernel_project.mli

src/plugins/server/request.ml

src/plugins/server/request.mli

src/plugins/server/syntax.ml

src/plugins/server/syntax.mli