Templates mount_option_remote_filesystems and mount_option_removable_partitions have weird keys

#### Description of problem:
There are multiple weird things in templates mount_option_remote_filesystems and mount_option_removable_partitions

Examples of weird things:
* mount_option_removable_partitions the parameter mountpoint is always set to `var_removable_partition` - why don't we hardcode it in templates, why is it a variable?
* mountpoint parameter is not used in any of mount_option_remote_filesystems templates but it's specified by rule.yml
* `filesystem` seems to be required for Bash remediations for both templates but it isn't specified by rule.yml
* `mount_has_to_exist` is not used in any of mount_option_remote_filesystems templates but it's specified by rule.yml

#### SCAP Security Guide Version:
current upstream as of 10th October 2019, head 85bdd8bbb8753f77f6c728811c89f026b76b4d8b

#### Operating System Version:
all

#### Steps to Reproduce:

1. check templates mount_option_remote_filesystems and mount_option_removable_partitions for all languages
2. check the used template paramters in rule.yml files
3. check callbacks in ssg/templates.py
4. compare what you have seen in 1, 2 and 3

#### Actual Results:
some undfined paramaters are used in rule.yml's and some parameters aren't populated at the same time

#### Expected Results:
parameters and rule.yml's are aligned, the parameters are properly documented in developer guide

#### Addition Information/Debugging Steps: