Similarly to f365a440 (software/ors-amarisoft: Merge gnb.jinja2.cfg into
enb.jinja2.cfg) merge LTE and NR configuration files for UEsim into single
config as the preparation for MultiRU - there UEsim will be also handling TDD,
FDD, LTE and NR cells and UEs all at the same time.

In this patch for now we only move code without changing it and wrap parts with
`if do_lte` and `if do_nr` correspondingly.  The end result of rendered
ue-lte.cfg and ue-nr.cfg stays practically the same as shown in the appendix.

/cc @jhuge, @lu.xu, @tomo, @xavier_thompson, @Daetalus

--------

Appendix. Diff for rendered ue-*.cfg before and after this patch.

```
$ ./pythonwitheggs slapos-render-config.py && git diff --no-index -w config/old/ config/out/
```

```diff
diff --git a/config/old/ue-lte.cfg b/config/out/ue-lte.cfg
index 7f1530daf..836a95e79 100644
--- a/config/old/ue-lte.cfg
+++ b/config/out/ue-lte.cfg
@@ -1,5 +1,6 @@

 #define N_RB_DL             50
+
 {
   log_options: "all.level=error,all.max_size=0,nas.level=debug,nas.max_size=1,rrc.level=debug,rrc.max_size=1,phy.level=info,file.rotate=1G,file.path=/dev/null",
   log_filename: "log/ue.log",
@@ -14,7 +15,8 @@ rf_driver: {
 },
   tx_gain: 60,
   rx_gain: 40,
-  cell_groups: [{
+  cell_groups: [
+  {
     multi_ue: true,
     cells: [
       {
@@ -27,7 +29,8 @@ rf_driver: {
     ],
     pdcch_decode_opt: false,
     pdcch_decode_opt_threshold: 0.1,
-  }],
+  },
+  ],
   ue_list: [
     {
     sim_algo: "milenage",
@@ -38,8 +41,8 @@ rf_driver: {
     impi: "",
     imsi: "001010123456789",
     K: "00112233445566778899aabbccddeeff",
-    rue_addr: "host1",
     ue_category: 12,
+    rue_addr: "host1",
     tun_setup_script: "ue-ifup",
     apn: "internet",
     }
diff --git a/config/old/ue-nr.cfg b/config/out/ue-nr.cfg
index 41758ab6f..631e1ab1e 100644
--- a/config/old/ue-nr.cfg
+++ b/config/out/ue-nr.cfg
@@ -1,3 +1,5 @@
+
+
 {
   log_options: "all.level=error,all.max_size=0,nas.level=debug,nas.max_size=1,rrc.level=debug,rrc.max_size=1,phy.level=info,file.rotate=1G,file.path=/dev/null",
   log_filename: "log/ue.log",
@@ -12,7 +14,8 @@ rf_driver: {
 },
   tx_gain: 60,
   rx_gain: 40,
-    cell_groups: [{
+  cell_groups: [
+  {
     group_type: "nr",
     multi_ue: false,
     cells: [{
@@ -26,7 +29,8 @@ rf_driver: {
       n_antenna_ul: 2,
       }
     ],
-    }],
+  },
+  ],
   ue_list: [
     {
     sim_algo: "milenage",
@@ -37,11 +41,11 @@ rf_driver: {
     impi: "",
     imsi: "001010123456789",
     K: "00112233445566778899aabbccddeeff",
-      rue_addr: "host2",
     as_release: 15,
     ue_category: "nr",
+    rue_addr: "host2",
     tun_setup_script: "ue-ifup",
     apn: "internet",
     }
-    ]
+  ],
 }
```