Implement add new section option

[nand-nor]

NOTE: Restricting this option to just config file mode, given the number of input parameters required of the user.

This mode will require user to provide a number of additional parameters, including (and may be expanded later) all fields for populating a section header.

Will require a number of post-injection fix-ups:

• [ ] Increment number of section headers in the exec header
• [ ] Add section header to SHT
• [ ] Adjust size of the segment within which the section is to be injected
• [ ] Adjust all following sections/segment offsets by section size, minding any alignments or byte padding, if new section injected anywhere before end of file
• [ ] if it is to be named, then the section header string table will need to be modified and all subsequent sections/segments adjusted by the number of bytes corresponding to added section name
• [ ] Adjust SHT offset in exec header by any potential offset due to above
• [ ] If any segments/sections come after the SHT (unlikely but possible), adjust them by size-of-sec-header bytes plus any incurred offset due to location of added section
• [ ] Likely more to be added that I am not thinking of right now. Adjust as needed

[nand-nor]

Note comment from issue #2 as it is relevant to post-addition fixups