tools: add some options and comments to shell.nix

[aduh95]

Triggered by #60902 and #60906

• adding withAmaro, withSQLite, and withSSL parameters (to be consistent with the withTemporal one that was recently added, and analogeous to --without-amaro, --without-sqlite, and --without-ssl configure.py flags). There are many other configure.py flags that do not have equivalent Nix parameter, however those 3 are special as they require a different build environment (that's not yet true for Amaro, but the long term goal is to include it as a native library instead of the current WASM approach)
• reorganizing the list of parameters (the current order doesn't have much logic to it, the file becomes much more readable when the parameters are grouped by their purpose)
• fixing a bug when passing --arg ccache null would not work as expected
• making use of lib.optional, lib.optionals, and lib.optionalString more consistent
• introducing a local needsRustCompiler as I expect we'll add more Rust compiled dependencies (currently it's only temporal_capi)